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Issues with gcc-arm-linux-gnueabihf package #38

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lkilo opened this issue Jul 29, 2018 · 17 comments
Closed

Issues with gcc-arm-linux-gnueabihf package #38

lkilo opened this issue Jul 29, 2018 · 17 comments

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@lkilo
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lkilo commented Jul 29, 2018

Hello Frank,

I've got some trouble installing the "gcc-arm-linux-gnueabihf" packet via apt.
I also tried manualy downloading the packet and installing it with dpkg but it says I've got the wrong architecture.
If it helps: uname -a output: "Linux server-00-bpi 4.4.70-BPI-R2-Kernel #1 SMP Tue Nov 28 10:59:01 CST 2017 armv7l armv7l armv7l GNU/Linux"

Regards

@frank-w
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frank-w commented Jul 29, 2018

You try to compile on r2 directly? Then you do not need this package...this package is called cross-compiler to build armhf-binaries on other architectures

@lkilo
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lkilo commented Jul 29, 2018

Ok. Well, I compiled the kernel on my BPI2 and received a "bananapi-r2-image-4.14-main_4.14.59-1_armhf.deb" package. I tried to install it via dpkg --install, it succeeded, but I'm still on the old kernel after a reboot. Do I need to copy the uimage manually into the BPI-BOOT partition?

@frank-w
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frank-w commented Jul 29, 2018

Please check with "mount" if /boot is your mounted boot-partition or simply a folder. Official images do not mount /boot and uboot did not found your kernel because it lay on BPI-ROOT/boot instead of BPI-BOOT

I'm also not sure if postinst works (add your new kernel to uenv.txt). deb-package function is currently experimental...working on postinst-scripts...it seems i need a preinst too to check for mounted /boot => added to build.sh

@lkilo
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lkilo commented Jul 29, 2018

There is nothing mounted to /boot.
While compiling kernel the script said that there's a problem with /boot, after I did choose to install the kernel directly.
I'm not sure what to do now.

@frank-w
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frank-w commented Jul 29, 2018

  • rename /boot to any other
  • create an empty /boot
  • mount /dev/mmcblk0p1 /boot
    try again install directly

@lkilo
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lkilo commented Jul 29, 2018

I just receive:
root@server-00-bpi:~# sudo dpkg --install /home/pi/bpi-r2-4.14/debian/bananapi-r2-image-4.14-main_4.14.59-1_armhf.deb
(Reading database ... 252129 files and directories currently installed.)
Preparing to unpack .../bananapi-r2-image-4.14-main_4.14.59-1_armhf.deb ...
Unpacking bananapi-r2-image-4.14-main (4.14.59-1) over (4.14.59-1) ...
dpkg: error processing archive /home/pi/bpi-r2-4.14/debian/bananapi-r2-image-4.14-main_4.14.59-1_armhf.deb (--install):
error setting ownership of './boot/bananapi/bpi-r2/linux/uImage_4.14.59-main': Operation not permitted
dpkg-deb: error: subprocess paste was killed by signal (Broken pipe)
/var/lib/dpkg/tmp.ci/postrm: 7: /var/lib/dpkg/tmp.ci/postrm: Syntax error: end of file unexpected (expecting ")")
dpkg: error while cleaning up:
subprocess new post-removal script returned error exit status 2
Errors were encountered while processing:
/home/pi/bpi-r2-4.14/debian/bananapi-r2-image-4.14-main_4.14.59-1_armhf.deb

@frank-w
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frank-w commented Jul 29, 2018

as i said, debian-package is experiemental...i try a bit to get the maintainer-scripts running for complete install...

previous version has only unpacked the files...in my local repo i fixed the syntax-error, but postinst-script seems not to be called

@lkilo
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lkilo commented Jul 29, 2018

Is there another way to get the 4.14 Kernel working? I did try the precompiled 4.14 kernel, but my bpi wont boot after copying the files from the archive.

@frank-w
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frank-w commented Jul 29, 2018

you can use build.sh to install directly on sd-card
if using the precompiled images you have to unpack the files to the BPI-OOT-folder to BPI-BOOT-Partition and from inside BPI-ROOT to BPI-ROOT

@lkilo
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lkilo commented Jul 29, 2018

The installation process succeeded, but now i got the same problem like with the precompiled kernel. The board isn't booting. The red lights lights for about 15 seconds and then turns off and nothing happens. Is there any way to fix that?

@frank-w
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frank-w commented Jul 29, 2018

if you have a usb2serial-cable you can connect to the board through debug-uart and look with minicom/putty what happens

https://www.fw-web.de/dokuwiki/doku.php?id=en/bpi-r2/debug-uart

fixed now the maintainers-scripts...have installed the 4.14.59 via deb in my ubuntu-image

@frank-w
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frank-w commented Jul 29, 2018

Btw if you switch from 4.4 to 4.14 you have to change network-config because of dsa-driver in 4.14.

@lkilo
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lkilo commented Jul 29, 2018

In the /etc/network/infterfaces file?

@frank-w
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frank-w commented Jul 29, 2018

Right. In my wiki you'll find an example https://www.fw-web.de/dokuwiki/doku.php?id=en:bpi-r2:network:start#permanent

but this should not poweroff the r2...it is simply not reachable because ip-config in 4.4 is done on ethx and in 4.14 on wan/lanx

@frank-w
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frank-w commented Jul 30, 2018

btw. Green and blue near gpio go off this is right,red should stay on...4.4 and mainline-kernel have a bug where thiis leds are stay on at boot which i have fixed

@lkilo
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lkilo commented Jul 30, 2018

Looking at the UART output, the BPI seems to boot correctly but fails to start Raise network interfaces.
It might be the /etc/network/interfaces file.

@frank-w
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frank-w commented Jul 30, 2018

Then just use the content from my wiki. simply replace ip/netmasq/gateway to your settings and don't forget config for eth0/eth1 these have not to be changed

@lkilo lkilo closed this as completed Jul 30, 2018
frank-w pushed a commit that referenced this issue Nov 13, 2018
commit 0711e8c upstream.

Please note that below oops is from an older kernel, but the same
race seems to be present in the upstream kernel too.

---8<---

The following panic was encountered during removing the ipmi_ssif
module:

[ 526.352555] Unable to handle kernel paging request at virtual address ffff000006923090
[ 526.360464] Mem abort info:
[ 526.363257] ESR = 0x86000007
[ 526.366304] Exception class = IABT (current EL), IL = 32 bits
[ 526.372221] SET = 0, FnV = 0
[ 526.375269] EA = 0, S1PTW = 0
[ 526.378405] swapper pgtable: 4k pages, 48-bit VAs, pgd = 000000008ae60416
[ 526.385185] [ffff000006923090] *pgd=000000bffcffe803, *pud=000000bffcffd803, *pmd=0000009f4731a003, *pte=0000000000000000
[ 526.396141] Internal error: Oops: 86000007 [#1] SMP
[ 526.401008] Modules linked in: nls_iso8859_1 ipmi_devintf joydev input_leds ipmi_msghandler shpchp sch_fq_codel ib_iser rdma_cm iw_cm ib_cm ib_core iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi ip_tables x_tables autofs4 btrfs zstd_compress raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c raid1 raid0 multipath linear i2c_smbus hid_generic usbhid uas hid usb_storage ast aes_ce_blk i2c_algo_bit aes_ce_cipher qede ttm crc32_ce ptp crct10dif_ce drm_kms_helper ghash_ce syscopyarea sha2_ce sysfillrect sysimgblt pps_core fb_sys_fops sha256_arm64 sha1_ce mpt3sas qed drm raid_class ahci scsi_transport_sas libahci gpio_xlp i2c_xlp9xx aes_neon_bs aes_neon_blk crypto_simd cryptd aes_arm64 [last unloaded: ipmi_ssif]
[ 526.468085] CPU: 125 PID: 0 Comm: swapper/125 Not tainted 4.15.0-35-generic #38~lp1775396+build.1
[ 526.476942] Hardware name: To be filled by O.E.M. Saber/Saber, BIOS 0ACKL022 08/14/2018
[ 526.484932] pstate: 00400009 (nzcv daif +PAN -UAO)
[ 526.489713] pc : 0xffff000006923090
[ 526.493198] lr : call_timer_fn+0x34/0x178
[ 526.497194] sp : ffff000009b0bdd0
[ 526.500496] x29: ffff000009b0bdd0 x28: 0000000000000082
[ 526.505796] x27: 0000000000000002 x26: ffff000009515188
[ 526.511096] x25: ffff000009515180 x24: ffff0000090f1018
[ 526.516396] x23: ffff000009519660 x22: dead000000000200
[ 526.521696] x21: ffff000006923090 x20: 0000000000000100
[ 526.526995] x19: ffff809eeb466a40 x18: 0000000000000000
[ 526.532295] x17: 000000000000000e x16: 0000000000000007
[ 526.537594] x15: 0000000000000000 x14: 071c71c71c71c71c
[ 526.542894] x13: 0000000000000000 x12: 0000000000000000
[ 526.548193] x11: 0000000000000001 x10: ffff000009b0be88
[ 526.553493] x9 : 0000000000000000 x8 : 0000000000000005
[ 526.558793] x7 : ffff80befc1f8528 x6 : 0000000000000020
[ 526.564092] x5 : 0000000000000040 x4 : 0000000020001b20
[ 526.569392] x3 : 0000000000000000 x2 : ffff809eeb466a40
[ 526.574692] x1 : ffff000006923090 x0 : ffff809eeb466a40
[ 526.579992] Process swapper/125 (pid: 0, stack limit = 0x000000002eb50acc)
[ 526.586854] Call trace:
[ 526.589289] 0xffff000006923090
[ 526.592419] expire_timers+0xc8/0x130
[ 526.596070] run_timer_softirq+0xec/0x1b0
[ 526.600070] __do_softirq+0x134/0x328
[ 526.603726] irq_exit+0xc8/0xe0
[ 526.606857] __handle_domain_irq+0x6c/0xc0
[ 526.610941] gic_handle_irq+0x84/0x188
[ 526.614679] el1_irq+0xe8/0x180
[ 526.617822] cpuidle_enter_state+0xa0/0x328
[ 526.621993] cpuidle_enter+0x34/0x48
[ 526.625564] call_cpuidle+0x44/0x70
[ 526.629040] do_idle+0x1b8/0x1f0
[ 526.632256] cpu_startup_entry+0x2c/0x30
[ 526.636174] secondary_start_kernel+0x11c/0x130
[ 526.640694] Code: bad PC value
[ 526.643800] ---[ end trace d020b0b8417c2498 ]---
[ 526.648404] Kernel panic - not syncing: Fatal exception in interrupt
[ 526.654778] SMP: stopping secondary CPUs
[ 526.658734] Kernel Offset: disabled
[ 526.662211] CPU features: 0x5800c38
[ 526.665688] Memory Limit: none
[ 526.668768] ---[ end Kernel panic - not syncing: Fatal exception in interrupt

Prevent mod_timer from arming a timer that was already removed by
del_timer during module unload.

Signed-off-by: Jan Glauber <jglauber@cavium.com>
Cc: <stable@vger.kernel.org> # 3.19
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
frank-w pushed a commit that referenced this issue Nov 13, 2018
commit 0711e8c upstream.

Please note that below oops is from an older kernel, but the same
race seems to be present in the upstream kernel too.

---8<---

The following panic was encountered during removing the ipmi_ssif
module:

[ 526.352555] Unable to handle kernel paging request at virtual address ffff000006923090
[ 526.360464] Mem abort info:
[ 526.363257] ESR = 0x86000007
[ 526.366304] Exception class = IABT (current EL), IL = 32 bits
[ 526.372221] SET = 0, FnV = 0
[ 526.375269] EA = 0, S1PTW = 0
[ 526.378405] swapper pgtable: 4k pages, 48-bit VAs, pgd = 000000008ae60416
[ 526.385185] [ffff000006923090] *pgd=000000bffcffe803, *pud=000000bffcffd803, *pmd=0000009f4731a003, *pte=0000000000000000
[ 526.396141] Internal error: Oops: 86000007 [#1] SMP
[ 526.401008] Modules linked in: nls_iso8859_1 ipmi_devintf joydev input_leds ipmi_msghandler shpchp sch_fq_codel ib_iser rdma_cm iw_cm ib_cm ib_core iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi ip_tables x_tables autofs4 btrfs zstd_compress raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c raid1 raid0 multipath linear i2c_smbus hid_generic usbhid uas hid usb_storage ast aes_ce_blk i2c_algo_bit aes_ce_cipher qede ttm crc32_ce ptp crct10dif_ce drm_kms_helper ghash_ce syscopyarea sha2_ce sysfillrect sysimgblt pps_core fb_sys_fops sha256_arm64 sha1_ce mpt3sas qed drm raid_class ahci scsi_transport_sas libahci gpio_xlp i2c_xlp9xx aes_neon_bs aes_neon_blk crypto_simd cryptd aes_arm64 [last unloaded: ipmi_ssif]
[ 526.468085] CPU: 125 PID: 0 Comm: swapper/125 Not tainted 4.15.0-35-generic #38~lp1775396+build.1
[ 526.476942] Hardware name: To be filled by O.E.M. Saber/Saber, BIOS 0ACKL022 08/14/2018
[ 526.484932] pstate: 00400009 (nzcv daif +PAN -UAO)
[ 526.489713] pc : 0xffff000006923090
[ 526.493198] lr : call_timer_fn+0x34/0x178
[ 526.497194] sp : ffff000009b0bdd0
[ 526.500496] x29: ffff000009b0bdd0 x28: 0000000000000082
[ 526.505796] x27: 0000000000000002 x26: ffff000009515188
[ 526.511096] x25: ffff000009515180 x24: ffff0000090f1018
[ 526.516396] x23: ffff000009519660 x22: dead000000000200
[ 526.521696] x21: ffff000006923090 x20: 0000000000000100
[ 526.526995] x19: ffff809eeb466a40 x18: 0000000000000000
[ 526.532295] x17: 000000000000000e x16: 0000000000000007
[ 526.537594] x15: 0000000000000000 x14: 071c71c71c71c71c
[ 526.542894] x13: 0000000000000000 x12: 0000000000000000
[ 526.548193] x11: 0000000000000001 x10: ffff000009b0be88
[ 526.553493] x9 : 0000000000000000 x8 : 0000000000000005
[ 526.558793] x7 : ffff80befc1f8528 x6 : 0000000000000020
[ 526.564092] x5 : 0000000000000040 x4 : 0000000020001b20
[ 526.569392] x3 : 0000000000000000 x2 : ffff809eeb466a40
[ 526.574692] x1 : ffff000006923090 x0 : ffff809eeb466a40
[ 526.579992] Process swapper/125 (pid: 0, stack limit = 0x000000002eb50acc)
[ 526.586854] Call trace:
[ 526.589289] 0xffff000006923090
[ 526.592419] expire_timers+0xc8/0x130
[ 526.596070] run_timer_softirq+0xec/0x1b0
[ 526.600070] __do_softirq+0x134/0x328
[ 526.603726] irq_exit+0xc8/0xe0
[ 526.606857] __handle_domain_irq+0x6c/0xc0
[ 526.610941] gic_handle_irq+0x84/0x188
[ 526.614679] el1_irq+0xe8/0x180
[ 526.617822] cpuidle_enter_state+0xa0/0x328
[ 526.621993] cpuidle_enter+0x34/0x48
[ 526.625564] call_cpuidle+0x44/0x70
[ 526.629040] do_idle+0x1b8/0x1f0
[ 526.632256] cpu_startup_entry+0x2c/0x30
[ 526.636174] secondary_start_kernel+0x11c/0x130
[ 526.640694] Code: bad PC value
[ 526.643800] ---[ end trace d020b0b8417c2498 ]---
[ 526.648404] Kernel panic - not syncing: Fatal exception in interrupt
[ 526.654778] SMP: stopping secondary CPUs
[ 526.658734] Kernel Offset: disabled
[ 526.662211] CPU features: 0x5800c38
[ 526.665688] Memory Limit: none
[ 526.668768] ---[ end Kernel panic - not syncing: Fatal exception in interrupt

Prevent mod_timer from arming a timer that was already removed by
del_timer during module unload.

Signed-off-by: Jan Glauber <jglauber@cavium.com>
Cc: <stable@vger.kernel.org> # 3.19
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
frank-w pushed a commit that referenced this issue Nov 13, 2018
commit 0711e8c upstream.

Please note that below oops is from an older kernel, but the same
race seems to be present in the upstream kernel too.

---8<---

The following panic was encountered during removing the ipmi_ssif
module:

[ 526.352555] Unable to handle kernel paging request at virtual address ffff000006923090
[ 526.360464] Mem abort info:
[ 526.363257] ESR = 0x86000007
[ 526.366304] Exception class = IABT (current EL), IL = 32 bits
[ 526.372221] SET = 0, FnV = 0
[ 526.375269] EA = 0, S1PTW = 0
[ 526.378405] swapper pgtable: 4k pages, 48-bit VAs, pgd = 000000008ae60416
[ 526.385185] [ffff000006923090] *pgd=000000bffcffe803, *pud=000000bffcffd803, *pmd=0000009f4731a003, *pte=0000000000000000
[ 526.396141] Internal error: Oops: 86000007 [#1] SMP
[ 526.401008] Modules linked in: nls_iso8859_1 ipmi_devintf joydev input_leds ipmi_msghandler shpchp sch_fq_codel ib_iser rdma_cm iw_cm ib_cm ib_core iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi ip_tables x_tables autofs4 btrfs zstd_compress raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c raid1 raid0 multipath linear i2c_smbus hid_generic usbhid uas hid usb_storage ast aes_ce_blk i2c_algo_bit aes_ce_cipher qede ttm crc32_ce ptp crct10dif_ce drm_kms_helper ghash_ce syscopyarea sha2_ce sysfillrect sysimgblt pps_core fb_sys_fops sha256_arm64 sha1_ce mpt3sas qed drm raid_class ahci scsi_transport_sas libahci gpio_xlp i2c_xlp9xx aes_neon_bs aes_neon_blk crypto_simd cryptd aes_arm64 [last unloaded: ipmi_ssif]
[ 526.468085] CPU: 125 PID: 0 Comm: swapper/125 Not tainted 4.15.0-35-generic #38~lp1775396+build.1
[ 526.476942] Hardware name: To be filled by O.E.M. Saber/Saber, BIOS 0ACKL022 08/14/2018
[ 526.484932] pstate: 00400009 (nzcv daif +PAN -UAO)
[ 526.489713] pc : 0xffff000006923090
[ 526.493198] lr : call_timer_fn+0x34/0x178
[ 526.497194] sp : ffff000009b0bdd0
[ 526.500496] x29: ffff000009b0bdd0 x28: 0000000000000082
[ 526.505796] x27: 0000000000000002 x26: ffff000009515188
[ 526.511096] x25: ffff000009515180 x24: ffff0000090f1018
[ 526.516396] x23: ffff000009519660 x22: dead000000000200
[ 526.521696] x21: ffff000006923090 x20: 0000000000000100
[ 526.526995] x19: ffff809eeb466a40 x18: 0000000000000000
[ 526.532295] x17: 000000000000000e x16: 0000000000000007
[ 526.537594] x15: 0000000000000000 x14: 071c71c71c71c71c
[ 526.542894] x13: 0000000000000000 x12: 0000000000000000
[ 526.548193] x11: 0000000000000001 x10: ffff000009b0be88
[ 526.553493] x9 : 0000000000000000 x8 : 0000000000000005
[ 526.558793] x7 : ffff80befc1f8528 x6 : 0000000000000020
[ 526.564092] x5 : 0000000000000040 x4 : 0000000020001b20
[ 526.569392] x3 : 0000000000000000 x2 : ffff809eeb466a40
[ 526.574692] x1 : ffff000006923090 x0 : ffff809eeb466a40
[ 526.579992] Process swapper/125 (pid: 0, stack limit = 0x000000002eb50acc)
[ 526.586854] Call trace:
[ 526.589289] 0xffff000006923090
[ 526.592419] expire_timers+0xc8/0x130
[ 526.596070] run_timer_softirq+0xec/0x1b0
[ 526.600070] __do_softirq+0x134/0x328
[ 526.603726] irq_exit+0xc8/0xe0
[ 526.606857] __handle_domain_irq+0x6c/0xc0
[ 526.610941] gic_handle_irq+0x84/0x188
[ 526.614679] el1_irq+0xe8/0x180
[ 526.617822] cpuidle_enter_state+0xa0/0x328
[ 526.621993] cpuidle_enter+0x34/0x48
[ 526.625564] call_cpuidle+0x44/0x70
[ 526.629040] do_idle+0x1b8/0x1f0
[ 526.632256] cpu_startup_entry+0x2c/0x30
[ 526.636174] secondary_start_kernel+0x11c/0x130
[ 526.640694] Code: bad PC value
[ 526.643800] ---[ end trace d020b0b8417c2498 ]---
[ 526.648404] Kernel panic - not syncing: Fatal exception in interrupt
[ 526.654778] SMP: stopping secondary CPUs
[ 526.658734] Kernel Offset: disabled
[ 526.662211] CPU features: 0x5800c38
[ 526.665688] Memory Limit: none
[ 526.668768] ---[ end Kernel panic - not syncing: Fatal exception in interrupt

Prevent mod_timer from arming a timer that was already removed by
del_timer during module unload.

Signed-off-by: Jan Glauber <jglauber@cavium.com>
Cc: <stable@vger.kernel.org> # 3.19
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
frank-w pushed a commit that referenced this issue Dec 17, 2018
Increase kasan instrumented kernel stack size from 32k to 64k. Other
architectures seems to get away with just doubling kernel stack size under
kasan, but on s390 this appears to be not enough due to bigger frame size.
The particular pain point is kasan inlined checks (CONFIG_KASAN_INLINE
vs CONFIG_KASAN_OUTLINE). With inlined checks one particular case hitting
stack overflow is fs sync on xfs filesystem:

 #0 [9a0681e8]  704 bytes  check_usage at 34b1fc
 #1 [9a0684a8]  432 bytes  check_usage at 34c710
 #2 [9a068658]  1048 bytes  validate_chain at 35044a
 #3 [9a068a70]  312 bytes  __lock_acquire at 3559fe
 #4 [9a068ba8]  440 bytes  lock_acquire at 3576ee
 #5 [9a068d60]  104 bytes  _raw_spin_lock at 21b44e0
 #6 [9a068dc8]  1992 bytes  enqueue_entity at 2dbf72
 #7 [9a069590]  1496 bytes  enqueue_task_fair at 2df5f0
 #8 [9a069b68]  64 bytes  ttwu_do_activate at 28f438
 #9 [9a069ba8]  552 bytes  try_to_wake_up at 298c4c
 #10 [9a069dd0]  168 bytes  wake_up_worker at 23f97c
 #11 [9a069e78]  200 bytes  insert_work at 23fc2e
 #12 [9a069f40]  648 bytes  __queue_work at 2487c0
 #13 [9a06a1c8]  200 bytes  __queue_delayed_work at 24db28
 #14 [9a06a290]  248 bytes  mod_delayed_work_on at 24de84
 #15 [9a06a388]  24 bytes  kblockd_mod_delayed_work_on at 153e2a0
 #16 [9a06a3a0]  288 bytes  __blk_mq_delay_run_hw_queue at 158168c
 #17 [9a06a4c0]  192 bytes  blk_mq_run_hw_queue at 1581a3c
 #18 [9a06a580]  184 bytes  blk_mq_sched_insert_requests at 15a2192
 #19 [9a06a638]  1024 bytes  blk_mq_flush_plug_list at 1590f3a
 #20 [9a06aa38]  704 bytes  blk_flush_plug_list at 1555028
 #21 [9a06acf8]  320 bytes  schedule at 219e476
 #22 [9a06ae38]  760 bytes  schedule_timeout at 21b0aac
 #23 [9a06b130]  408 bytes  wait_for_common at 21a1706
 #24 [9a06b2c8]  360 bytes  xfs_buf_iowait at fa1540
 #25 [9a06b430]  256 bytes  __xfs_buf_submit at fadae6
 #26 [9a06b530]  264 bytes  xfs_buf_read_map at fae3f6
 #27 [9a06b638]  656 bytes  xfs_trans_read_buf_map at 10ac9a8
 #28 [9a06b8c8]  304 bytes  xfs_btree_kill_root at e72426
 #29 [9a06b9f8]  288 bytes  xfs_btree_lookup_get_block at e7bc5e
 #30 [9a06bb18]  624 bytes  xfs_btree_lookup at e7e1a6
 #31 [9a06bd88]  2664 bytes  xfs_alloc_ag_vextent_near at dfa070
 #32 [9a06c7f0]  144 bytes  xfs_alloc_ag_vextent at dff3ca
 #33 [9a06c880]  1128 bytes  xfs_alloc_vextent at e05fce
 #34 [9a06cce8]  584 bytes  xfs_bmap_btalloc at e58342
 #35 [9a06cf30]  1336 bytes  xfs_bmapi_write at e618de
 #36 [9a06d468]  776 bytes  xfs_iomap_write_allocate at ff678e
 #37 [9a06d770]  720 bytes  xfs_map_blocks at f82af8
 #38 [9a06da40]  928 bytes  xfs_writepage_map at f83cd6
 #39 [9a06dde0]  320 bytes  xfs_do_writepage at f85872
 #40 [9a06df20]  1320 bytes  write_cache_pages at 73dfe8
 #41 [9a06e448]  208 bytes  xfs_vm_writepages at f7f892
 #42 [9a06e518]  88 bytes  do_writepages at 73fe6a
 #43 [9a06e570]  872 bytes  __writeback_single_inode at a20cb6
 #44 [9a06e8d8]  664 bytes  writeback_sb_inodes at a23be2
 #45 [9a06eb70]  296 bytes  __writeback_inodes_wb at a242e0
 #46 [9a06ec98]  928 bytes  wb_writeback at a2500e
 #47 [9a06f038]  848 bytes  wb_do_writeback at a260ae
 #48 [9a06f388]  536 bytes  wb_workfn at a28228
 #49 [9a06f5a0]  1088 bytes  process_one_work at 24a234
 #50 [9a06f9e0]  1120 bytes  worker_thread at 24ba26
 #51 [9a06fe40]  104 bytes  kthread at 26545a
 #52 [9a06fea8]             kernel_thread_starter at 21b6b62

To be able to increase the stack size to 64k reuse LLILL instruction
in __switch_to function to load 64k - STACK_FRAME_OVERHEAD - __PT_SIZE
(65192) value as unsigned.

Reported-by: Benjamin Block <bblock@linux.ibm.com>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
frank-w pushed a commit that referenced this issue Jun 28, 2019
When user space sends invalid information in RTA_MULTIPATH, the nexthop
list in ip6_route_multipath_add() is empty and 'rt_notif' is set to
NULL.

The code that emits the in-kernel notifications does not check for this
condition, which results in a NULL pointer dereference [1].

Fix this by bailing earlier in the function if the parsed nexthop list
is empty. This is consistent with the corresponding IPv4 code.

v2:
* Check if parsed nexthop list is empty and bail with extack set

[1]
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 9190 Comm: syz-executor149 Not tainted 5.2.0-rc5+ #38
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
RIP: 0010:call_fib6_multipath_entry_notifiers+0xd1/0x1a0
net/ipv6/ip6_fib.c:396
Code: 8b b5 30 ff ff ff 48 c7 85 68 ff ff ff 00 00 00 00 48 c7 85 70 ff ff
ff 00 00 00 00 89 45 88 4c 89 e0 48 c1 e8 03 4c 89 65 80 <42> 80 3c 28 00
0f 85 9a 00 00 00 48 b8 00 00 00 00 00 fc ff df 4d
RSP: 0018:ffff88809788f2c0 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 1ffff11012f11e59 RCX: 00000000ffffffff
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffff88809788f390 R08: ffff88809788f8c0 R09: 000000000000000c
R10: ffff88809788f5d8 R11: ffff88809788f527 R12: 0000000000000000
R13: dffffc0000000000 R14: ffff88809788f8c0 R15: ffffffff89541d80
FS:  000055555632c880(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000080 CR3: 000000009ba7c000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
  ip6_route_multipath_add+0xc55/0x1490 net/ipv6/route.c:5094
  inet6_rtm_newroute+0xed/0x180 net/ipv6/route.c:5208
  rtnetlink_rcv_msg+0x463/0xb00 net/core/rtnetlink.c:5219
  netlink_rcv_skb+0x177/0x450 net/netlink/af_netlink.c:2477
  rtnetlink_rcv+0x1d/0x30 net/core/rtnetlink.c:5237
  netlink_unicast_kernel net/netlink/af_netlink.c:1302 [inline]
  netlink_unicast+0x531/0x710 net/netlink/af_netlink.c:1328
  netlink_sendmsg+0x8ae/0xd70 net/netlink/af_netlink.c:1917
  sock_sendmsg_nosec net/socket.c:646 [inline]
  sock_sendmsg+0xd7/0x130 net/socket.c:665
  ___sys_sendmsg+0x803/0x920 net/socket.c:2286
  __sys_sendmsg+0x105/0x1d0 net/socket.c:2324
  __do_sys_sendmsg net/socket.c:2333 [inline]
  __se_sys_sendmsg net/socket.c:2331 [inline]
  __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2331
  do_syscall_64+0xfd/0x680 arch/x86/entry/common.c:301
  entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x4401f9
Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 48 89 f8 48 89 f7
48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff
ff 0f 83 fb 13 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffc09fd0028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 00000000004401f9
RDX: 0000000000000000 RSI: 0000000020000080 RDI: 0000000000000003
RBP: 00000000006ca018 R08: 0000000000000000 R09: 00000000004002c8
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000401a80
R13: 0000000000401b10 R14: 0000000000000000 R15: 0000000000000000

Reported-by: syzbot+382566d339d52cd1a204@syzkaller.appspotmail.com
Fixes: ebee3ca ("ipv6: Add IPv6 multipath notifications for add / replace")
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
frank-w pushed a commit that referenced this issue Sep 27, 2019
commit 0711e8c upstream.

Please note that below oops is from an older kernel, but the same
race seems to be present in the upstream kernel too.

---8<---

The following panic was encountered during removing the ipmi_ssif
module:

[ 526.352555] Unable to handle kernel paging request at virtual address ffff000006923090
[ 526.360464] Mem abort info:
[ 526.363257] ESR = 0x86000007
[ 526.366304] Exception class = IABT (current EL), IL = 32 bits
[ 526.372221] SET = 0, FnV = 0
[ 526.375269] EA = 0, S1PTW = 0
[ 526.378405] swapper pgtable: 4k pages, 48-bit VAs, pgd = 000000008ae60416
[ 526.385185] [ffff000006923090] *pgd=000000bffcffe803, *pud=000000bffcffd803, *pmd=0000009f4731a003, *pte=0000000000000000
[ 526.396141] Internal error: Oops: 86000007 [#1] SMP
[ 526.401008] Modules linked in: nls_iso8859_1 ipmi_devintf joydev input_leds ipmi_msghandler shpchp sch_fq_codel ib_iser rdma_cm iw_cm ib_cm ib_core iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi ip_tables x_tables autofs4 btrfs zstd_compress raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c raid1 raid0 multipath linear i2c_smbus hid_generic usbhid uas hid usb_storage ast aes_ce_blk i2c_algo_bit aes_ce_cipher qede ttm crc32_ce ptp crct10dif_ce drm_kms_helper ghash_ce syscopyarea sha2_ce sysfillrect sysimgblt pps_core fb_sys_fops sha256_arm64 sha1_ce mpt3sas qed drm raid_class ahci scsi_transport_sas libahci gpio_xlp i2c_xlp9xx aes_neon_bs aes_neon_blk crypto_simd cryptd aes_arm64 [last unloaded: ipmi_ssif]
[ 526.468085] CPU: 125 PID: 0 Comm: swapper/125 Not tainted 4.15.0-35-generic #38~lp1775396+build.1
[ 526.476942] Hardware name: To be filled by O.E.M. Saber/Saber, BIOS 0ACKL022 08/14/2018
[ 526.484932] pstate: 00400009 (nzcv daif +PAN -UAO)
[ 526.489713] pc : 0xffff000006923090
[ 526.493198] lr : call_timer_fn+0x34/0x178
[ 526.497194] sp : ffff000009b0bdd0
[ 526.500496] x29: ffff000009b0bdd0 x28: 0000000000000082
[ 526.505796] x27: 0000000000000002 x26: ffff000009515188
[ 526.511096] x25: ffff000009515180 x24: ffff0000090f1018
[ 526.516396] x23: ffff000009519660 x22: dead000000000200
[ 526.521696] x21: ffff000006923090 x20: 0000000000000100
[ 526.526995] x19: ffff809eeb466a40 x18: 0000000000000000
[ 526.532295] x17: 000000000000000e x16: 0000000000000007
[ 526.537594] x15: 0000000000000000 x14: 071c71c71c71c71c
[ 526.542894] x13: 0000000000000000 x12: 0000000000000000
[ 526.548193] x11: 0000000000000001 x10: ffff000009b0be88
[ 526.553493] x9 : 0000000000000000 x8 : 0000000000000005
[ 526.558793] x7 : ffff80befc1f8528 x6 : 0000000000000020
[ 526.564092] x5 : 0000000000000040 x4 : 0000000020001b20
[ 526.569392] x3 : 0000000000000000 x2 : ffff809eeb466a40
[ 526.574692] x1 : ffff000006923090 x0 : ffff809eeb466a40
[ 526.579992] Process swapper/125 (pid: 0, stack limit = 0x000000002eb50acc)
[ 526.586854] Call trace:
[ 526.589289] 0xffff000006923090
[ 526.592419] expire_timers+0xc8/0x130
[ 526.596070] run_timer_softirq+0xec/0x1b0
[ 526.600070] __do_softirq+0x134/0x328
[ 526.603726] irq_exit+0xc8/0xe0
[ 526.606857] __handle_domain_irq+0x6c/0xc0
[ 526.610941] gic_handle_irq+0x84/0x188
[ 526.614679] el1_irq+0xe8/0x180
[ 526.617822] cpuidle_enter_state+0xa0/0x328
[ 526.621993] cpuidle_enter+0x34/0x48
[ 526.625564] call_cpuidle+0x44/0x70
[ 526.629040] do_idle+0x1b8/0x1f0
[ 526.632256] cpu_startup_entry+0x2c/0x30
[ 526.636174] secondary_start_kernel+0x11c/0x130
[ 526.640694] Code: bad PC value
[ 526.643800] ---[ end trace d020b0b8417c2498 ]---
[ 526.648404] Kernel panic - not syncing: Fatal exception in interrupt
[ 526.654778] SMP: stopping secondary CPUs
[ 526.658734] Kernel Offset: disabled
[ 526.662211] CPU features: 0x5800c38
[ 526.665688] Memory Limit: none
[ 526.668768] ---[ end Kernel panic - not syncing: Fatal exception in interrupt

Prevent mod_timer from arming a timer that was already removed by
del_timer during module unload.

Signed-off-by: Jan Glauber <jglauber@cavium.com>
Cc: <stable@vger.kernel.org> # 3.19
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
frank-w pushed a commit that referenced this issue Oct 29, 2019
Connecting a vCPU to a XIVE KVM device means establishing a 1:1
association between a vCPU id and the offset (VP id) of a VP
structure within a fixed size block of VPs. We currently try to
enforce the 1:1 relationship by checking that a vCPU with the
same id isn't already connected. This is good but unfortunately
not enough because we don't map VP ids to raw vCPU ids but to
packed vCPU ids, and the packing function kvmppc_pack_vcpu_id()
isn't bijective by design. We got away with it because QEMU passes
vCPU ids that fit well in the packing pattern. But nothing prevents
userspace to come up with a forged vCPU id resulting in a packed id
collision which causes the KVM device to associate two vCPUs to the
same VP. This greatly confuses the irq layer and ultimately crashes
the kernel, as shown below.

Example: a guest with 1 guest thread per core, a core stride of
8 and 300 vCPUs has vCPU ids 0,8,16...2392. If QEMU is patched to
inject at some point an invalid vCPU id 348, which is the packed
version of itself and 2392, we get:

genirq: Flags mismatch irq 199. 00010000 (kvm-2-2392) vs. 00010000 (kvm-2-348)
CPU: 24 PID: 88176 Comm: qemu-system-ppc Not tainted 5.3.0-xive-nr-servers-5.3-gku+ #38
Call Trace:
[c000003f7f9937e0] [c000000000c0110c] dump_stack+0xb0/0xf4 (unreliable)
[c000003f7f993820] [c0000000001cb480] __setup_irq+0xa70/0xad0
[c000003f7f9938d0] [c0000000001cb75c] request_threaded_irq+0x13c/0x260
[c000003f7f993940] [c00800000d44e7ac] kvmppc_xive_attach_escalation+0x104/0x270 [kvm]
[c000003f7f9939d0] [c00800000d45013c] kvmppc_xive_connect_vcpu+0x424/0x620 [kvm]
[c000003f7f993ac0] [c00800000d444428] kvm_arch_vcpu_ioctl+0x260/0x448 [kvm]
[c000003f7f993b90] [c00800000d43593c] kvm_vcpu_ioctl+0x154/0x7c8 [kvm]
[c000003f7f993d00] [c0000000004840f0] do_vfs_ioctl+0xe0/0xc30
[c000003f7f993db0] [c000000000484d44] ksys_ioctl+0x104/0x120
[c000003f7f993e00] [c000000000484d88] sys_ioctl+0x28/0x80
[c000003f7f993e20] [c00000000000b278] system_call+0x5c/0x68
xive-kvm: Failed to request escalation interrupt for queue 0 of VCPU 2392
------------[ cut here ]------------
remove_proc_entry: removing non-empty directory 'irq/199', leaking at least 'kvm-2-348'
WARNING: CPU: 24 PID: 88176 at /home/greg/Work/linux/kernel-kvm-ppc/fs/proc/generic.c:684 remove_proc_entry+0x1ec/0x200
Modules linked in: kvm_hv kvm dm_mod vhost_net vhost tap xt_CHECKSUM iptable_mangle xt_MASQUERADE iptable_nat nf_nat xt_conntrack nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 ipt_REJECT nf_reject_ipv4 tun bridge stp llc ebtable_filter ebtables ip6table_filter ip6_tables iptable_filter squashfs loop fuse i2c_dev sg ofpart ocxl powernv_flash at24 xts mtd uio_pdrv_genirq vmx_crypto opal_prd ipmi_powernv uio ipmi_devintf ipmi_msghandler ibmpowernv ib_iser rdma_cm iw_cm ib_cm ib_core iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi ip_tables ext4 mbcache jbd2 raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor xor async_tx raid6_pq libcrc32c raid1 raid0 linear sd_mod ast i2c_algo_bit drm_vram_helper ttm drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops drm ahci libahci libata tg3 drm_panel_orientation_quirks [last unloaded: kvm]
CPU: 24 PID: 88176 Comm: qemu-system-ppc Not tainted 5.3.0-xive-nr-servers-5.3-gku+ #38
NIP:  c00000000053b0cc LR: c00000000053b0c8 CTR: c0000000000ba3b0
REGS: c000003f7f9934b0 TRAP: 0700   Not tainted  (5.3.0-xive-nr-servers-5.3-gku+)
MSR:  9000000000029033 <SF,HV,EE,ME,IR,DR,RI,LE>  CR: 48228222  XER: 20040000
CFAR: c000000000131a50 IRQMASK: 0
GPR00: c00000000053b0c8 c000003f7f993740 c0000000015ec500 0000000000000057
GPR04: 0000000000000001 0000000000000000 000049fb98484262 0000000000001bcf
GPR08: 0000000000000007 0000000000000007 0000000000000001 9000000000001033
GPR12: 0000000000008000 c000003ffffeb800 0000000000000000 000000012f4ce5a1
GPR16: 000000012ef5a0c8 0000000000000000 000000012f113bb0 0000000000000000
GPR20: 000000012f45d918 c000003f863758b0 c000003f86375870 0000000000000006
GPR24: c000003f86375a30 0000000000000007 c0002039373d9020 c0000000014c4a48
GPR28: 0000000000000001 c000003fe62a4f6b c00020394b2e9fab c000003fe62a4ec0
NIP [c00000000053b0cc] remove_proc_entry+0x1ec/0x200
LR [c00000000053b0c8] remove_proc_entry+0x1e8/0x200
Call Trace:
[c000003f7f993740] [c00000000053b0c8] remove_proc_entry+0x1e8/0x200 (unreliable)
[c000003f7f9937e0] [c0000000001d3654] unregister_irq_proc+0x114/0x150
[c000003f7f993880] [c0000000001c6284] free_desc+0x54/0xb0
[c000003f7f9938c0] [c0000000001c65ec] irq_free_descs+0xac/0x100
[c000003f7f993910] [c0000000001d1ff8] irq_dispose_mapping+0x68/0x80
[c000003f7f993940] [c00800000d44e8a4] kvmppc_xive_attach_escalation+0x1fc/0x270 [kvm]
[c000003f7f9939d0] [c00800000d45013c] kvmppc_xive_connect_vcpu+0x424/0x620 [kvm]
[c000003f7f993ac0] [c00800000d444428] kvm_arch_vcpu_ioctl+0x260/0x448 [kvm]
[c000003f7f993b90] [c00800000d43593c] kvm_vcpu_ioctl+0x154/0x7c8 [kvm]
[c000003f7f993d00] [c0000000004840f0] do_vfs_ioctl+0xe0/0xc30
[c000003f7f993db0] [c000000000484d44] ksys_ioctl+0x104/0x120
[c000003f7f993e00] [c000000000484d88] sys_ioctl+0x28/0x80
[c000003f7f993e20] [c00000000000b278] system_call+0x5c/0x68
Instruction dump:
2c230000 41820008 3923ff78 e8e900a0 3c82ff69 3c62ff8d 7fa6eb78 7fc5f378
3884f080 3863b948 4bbf6925 60000000 <0fe00000> 4bffff7c fba10088 4bbf6e41
---[ end trace b925b67a74a1d8d1 ]---
BUG: Kernel NULL pointer dereference at 0x00000010
Faulting instruction address: 0xc00800000d44fc04
Oops: Kernel access of bad area, sig: 11 [#1]
LE PAGE_SIZE=64K MMU=Radix MMU=Hash SMP NR_CPUS=2048 NUMA PowerNV
Modules linked in: kvm_hv kvm dm_mod vhost_net vhost tap xt_CHECKSUM iptable_mangle xt_MASQUERADE iptable_nat nf_nat xt_conntrack nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 ipt_REJECT nf_reject_ipv4 tun bridge stp llc ebtable_filter ebtables ip6table_filter ip6_tables iptable_filter squashfs loop fuse i2c_dev sg ofpart ocxl powernv_flash at24 xts mtd uio_pdrv_genirq vmx_crypto opal_prd ipmi_powernv uio ipmi_devintf ipmi_msghandler ibmpowernv ib_iser rdma_cm iw_cm ib_cm ib_core iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi ip_tables ext4 mbcache jbd2 raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor xor async_tx raid6_pq libcrc32c raid1 raid0 linear sd_mod ast i2c_algo_bit drm_vram_helper ttm drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops drm ahci libahci libata tg3 drm_panel_orientation_quirks [last unloaded: kvm]
CPU: 24 PID: 88176 Comm: qemu-system-ppc Tainted: G        W         5.3.0-xive-nr-servers-5.3-gku+ #38
NIP:  c00800000d44fc04 LR: c00800000d44fc00 CTR: c0000000001cd970
REGS: c000003f7f9938e0 TRAP: 0300   Tainted: G        W          (5.3.0-xive-nr-servers-5.3-gku+)
MSR:  9000000000009033 <SF,HV,EE,ME,IR,DR,RI,LE>  CR: 24228882  XER: 20040000
CFAR: c0000000001cd9ac DAR: 0000000000000010 DSISR: 40000000 IRQMASK: 0
GPR00: c00800000d44fc00 c000003f7f993b70 c00800000d468300 0000000000000000
GPR04: 00000000000000c7 0000000000000000 0000000000000000 c000003ffacd06d8
GPR08: 0000000000000000 c000003ffacd0738 0000000000000000 fffffffffffffffd
GPR12: 0000000000000040 c000003ffffeb800 0000000000000000 000000012f4ce5a1
GPR16: 000000012ef5a0c8 0000000000000000 000000012f113bb0 0000000000000000
GPR20: 000000012f45d918 00007ffffe0d9a80 000000012f4f5df0 000000012ef8c9f8
GPR24: 0000000000000001 0000000000000000 c000003fe4501ed0 c000003f8b1d0000
GPR28: c0000033314689c0 c000003fe4501c00 c000003fe4501e70 c000003fe4501e90
NIP [c00800000d44fc04] kvmppc_xive_cleanup_vcpu+0xfc/0x210 [kvm]
LR [c00800000d44fc00] kvmppc_xive_cleanup_vcpu+0xf8/0x210 [kvm]
Call Trace:
[c000003f7f993b70] [c00800000d44fc00] kvmppc_xive_cleanup_vcpu+0xf8/0x210 [kvm] (unreliable)
[c000003f7f993bd0] [c00800000d450bd4] kvmppc_xive_release+0xdc/0x1b0 [kvm]
[c000003f7f993c30] [c00800000d436a98] kvm_device_release+0xb0/0x110 [kvm]
[c000003f7f993c70] [c00000000046730c] __fput+0xec/0x320
[c000003f7f993cd0] [c000000000164ae0] task_work_run+0x150/0x1c0
[c000003f7f993d30] [c000000000025034] do_notify_resume+0x304/0x440
[c000003f7f993e20] [c00000000000dcc4] ret_from_except_lite+0x70/0x74
Instruction dump:
3bff0008 7fbfd040 419e0054 847e0004 2fa30000 419effec e93d0000 8929203c
2f890000 419effb8 4800821d e8410018 <e9230010> e9490008 9b2a0039 7c0004ac
---[ end trace b925b67a74a1d8d2 ]---

Kernel panic - not syncing: Fatal exception

This affects both XIVE and XICS-on-XIVE devices since the beginning.

Check the VP id instead of the vCPU id when a new vCPU is connected.
The allocation of the XIVE CPU structure in kvmppc_xive_connect_vcpu()
is moved after the check to avoid the need for rollback.

Cc: stable@vger.kernel.org # v4.12+
Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
frank-w pushed a commit that referenced this issue Dec 22, 2019
[ Upstream commit d02ba2a ]

pppol2tp_release uses call_rcu to put the final ref on its socket. But
the session object doesn't hold a ref on the session socket so may be
freed while the pppol2tp_put_sk RCU callback is scheduled. Fix this by
having the session hold a ref on its socket until the session is
destroyed. It is this ref that is dropped via call_rcu.

Sessions are also deleted via l2tp_tunnel_closeall. This must now also put
the final ref via call_rcu. So move the call_rcu call site into
pppol2tp_session_close so that this happens in both destroy paths. A
common destroy path should really be implemented, perhaps with
l2tp_tunnel_closeall calling l2tp_session_delete like pppol2tp_release
does, but this will be looked at later.

ODEBUG: activate active (active state 1) object type: rcu_head hint:           (null)
WARNING: CPU: 3 PID: 13407 at lib/debugobjects.c:291 debug_print_object+0x166/0x220
Modules linked in:
CPU: 3 PID: 13407 Comm: syzbot_19c09769 Not tainted 4.16.0-rc2+ #38
Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
RIP: 0010:debug_print_object+0x166/0x220
RSP: 0018:ffff880013647a00 EFLAGS: 00010082
RAX: dffffc0000000008 RBX: 0000000000000003 RCX: ffffffff814d3333
RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff88001a59f6d0
RBP: ffff880013647a40 R08: 0000000000000000 R09: 0000000000000001
R10: ffff8800136479a8 R11: 0000000000000000 R12: 0000000000000001
R13: ffffffff86161420 R14: ffffffff85648b60 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff88001a580000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020e77000 CR3: 0000000006022000 CR4: 00000000000006e0
Call Trace:
 debug_object_activate+0x38b/0x530
 ? debug_object_assert_init+0x3b0/0x3b0
 ? __mutex_unlock_slowpath+0x85/0x8b0
 ? pppol2tp_session_destruct+0x110/0x110
 __call_rcu.constprop.66+0x39/0x890
 ? __call_rcu.constprop.66+0x39/0x890
 call_rcu_sched+0x17/0x20
 pppol2tp_release+0x2c7/0x440
 ? fcntl_setlk+0xca0/0xca0
 ? sock_alloc_file+0x340/0x340
 sock_release+0x92/0x1e0
 sock_close+0x1b/0x20
 __fput+0x296/0x6e0
 ____fput+0x1a/0x20
 task_work_run+0x127/0x1a0
 do_exit+0x7f9/0x2ce0
 ? SYSC_connect+0x212/0x310
 ? mm_update_next_owner+0x690/0x690
 ? up_read+0x1f/0x40
 ? __do_page_fault+0x3c8/0xca0
 do_group_exit+0x10d/0x330
 ? do_group_exit+0x330/0x330
 SyS_exit_group+0x22/0x30
 do_syscall_64+0x1e0/0x730
 ? trace_hardirqs_off_thunk+0x1a/0x1c
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x7f362e471259
RSP: 002b:00007ffe389abe08 EFLAGS: 00000202 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f362e471259
RDX: 00007f362e471259 RSI: 000000000000002e RDI: 0000000000000000
RBP: 00007ffe389abe30 R08: 0000000000000000 R09: 00007f362e944270
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000400b60
R13: 00007ffe389abf50 R14: 0000000000000000 R15: 0000000000000000
Code: 8d 3c dd a0 8f 64 85 48 89 fa 48 c1 ea 03 80 3c 02 00 75 7b 48 8b 14 dd a0 8f 64 85 4c 89 f6 48 c7 c7 20 85 64 85 e
8 2a 55 14 ff <0f> 0b 83 05 ad 2a 68 04 01 48 83 c4 18 5b 41 5c 41 5d 41 5e 41

Fixes: ee40fb2 ("l2tp: protect sock pointer of struct pppol2tp_session with RCU")
Signed-off-by: James Chapman <jchapman@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
frank-w pushed a commit that referenced this issue Nov 16, 2020
…tect_depth

This oops manifests itself on the following hardware:
01:00.0 VGA compatible controller: NVIDIA Corporation G98M [GeForce G 103M] (rev a1)

Oct 09 14:17:46 lp-sasha kernel: BUG: kernel NULL pointer dereference, address: 0000000000000000
Oct 09 14:17:46 lp-sasha kernel: #PF: supervisor read access in kernel mode
Oct 09 14:17:46 lp-sasha kernel: #PF: error_code(0x0000) - not-present page
Oct 09 14:17:46 lp-sasha kernel: PGD 0 P4D 0
Oct 09 14:17:46 lp-sasha kernel: Oops: 0000 [#1] SMP PTI
Oct 09 14:17:46 lp-sasha kernel: CPU: 1 PID: 191 Comm: systemd-udevd Not tainted 5.9.0-rc8-next-20201009 #38
Oct 09 14:17:46 lp-sasha kernel: Hardware name: Hewlett-Packard Compaq Presario CQ61 Notebook PC/306A, BIOS F.03 03/23/2009
Oct 09 14:17:46 lp-sasha kernel: RIP: 0010:nouveau_connector_detect_depth+0x71/0xc0 [nouveau]
Oct 09 14:17:46 lp-sasha kernel: Code: 0a 00 00 48 8b 49 48 c7 87 b8 00 00 00 06 00 00 00 80 b9 4d 0a 00 00 00 75 1e 83 fa 41 75 05 48 85 c0 75 29 8b 81 10 0d 00 00 <39> 06 7c 25 f6 81 14 0d 00 00 02 75 b7 c3 80 b9 0c 0d 00 00 00 75
Oct 09 14:17:46 lp-sasha kernel: RSP: 0018:ffffc9000028f8c0 EFLAGS: 00010297
Oct 09 14:17:46 lp-sasha kernel: RAX: 0000000000014c08 RBX: ffff8880369d4000 RCX: ffff8880369d3000
Oct 09 14:17:46 lp-sasha kernel: RDX: 0000000000000040 RSI: 0000000000000000 RDI: ffff8880369d4000
Oct 09 14:17:46 lp-sasha kernel: RBP: ffff88800601cc00 R08: ffff8880051da298 R09: ffffffff8226201a
Oct 09 14:17:46 lp-sasha kernel: R10: ffff88800469aa80 R11: ffff888004c84ff8 R12: 0000000000000000
Oct 09 14:17:46 lp-sasha kernel: R13: ffff8880051da000 R14: 0000000000002000 R15: 0000000000000003
Oct 09 14:17:46 lp-sasha kernel: FS:  00007fd0192b3440(0000) GS:ffff8880bc900000(0000) knlGS:0000000000000000
Oct 09 14:17:46 lp-sasha kernel: CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
Oct 09 14:17:46 lp-sasha kernel: CR2: 0000000000000000 CR3: 0000000004976000 CR4: 00000000000006e0
Oct 09 14:17:46 lp-sasha kernel: Call Trace:
Oct 09 14:17:46 lp-sasha kernel:  nouveau_connector_get_modes+0x1e6/0x240 [nouveau]
Oct 09 14:17:46 lp-sasha kernel:  ? kfree+0xb9/0x240
Oct 09 14:17:46 lp-sasha kernel:  ? drm_connector_list_iter_next+0x7c/0xa0
Oct 09 14:17:46 lp-sasha kernel:  drm_helper_probe_single_connector_modes+0x1ba/0x7c0
Oct 09 14:17:46 lp-sasha kernel:  drm_client_modeset_probe+0x27e/0x1360
Oct 09 14:17:46 lp-sasha kernel:  ? nvif_object_sclass_put+0xc/0x20 [nouveau]
Oct 09 14:17:46 lp-sasha kernel:  ? nouveau_cli_init+0x3cc/0x440 [nouveau]
Oct 09 14:17:46 lp-sasha kernel:  ? ktime_get_mono_fast_ns+0x49/0xa0
Oct 09 14:17:46 lp-sasha kernel:  ? nouveau_drm_open+0x4e/0x180 [nouveau]
Oct 09 14:17:46 lp-sasha kernel:  __drm_fb_helper_initial_config_and_unlock+0x3f/0x4a0
Oct 09 14:17:46 lp-sasha kernel:  ? drm_file_alloc+0x18f/0x260
Oct 09 14:17:46 lp-sasha kernel:  ? mutex_lock+0x9/0x40
Oct 09 14:17:46 lp-sasha kernel:  ? drm_client_init+0x110/0x160
Oct 09 14:17:46 lp-sasha kernel:  nouveau_fbcon_init+0x14d/0x1c0 [nouveau]
Oct 09 14:17:46 lp-sasha kernel:  nouveau_drm_device_init+0x1c0/0x880 [nouveau]
Oct 09 14:17:46 lp-sasha kernel:  nouveau_drm_probe+0x11a/0x1e0 [nouveau]
Oct 09 14:17:46 lp-sasha kernel:  pci_device_probe+0xcd/0x140
Oct 09 14:17:46 lp-sasha kernel:  really_probe+0xd8/0x400
Oct 09 14:17:46 lp-sasha kernel:  driver_probe_device+0x4a/0xa0
Oct 09 14:17:46 lp-sasha kernel:  device_driver_attach+0x9c/0xc0
Oct 09 14:17:46 lp-sasha kernel:  __driver_attach+0x6f/0x100
Oct 09 14:17:46 lp-sasha kernel:  ? device_driver_attach+0xc0/0xc0
Oct 09 14:17:46 lp-sasha kernel:  bus_for_each_dev+0x75/0xc0
Oct 09 14:17:46 lp-sasha kernel:  bus_add_driver+0x106/0x1c0
Oct 09 14:17:46 lp-sasha kernel:  driver_register+0x86/0xe0
Oct 09 14:17:46 lp-sasha kernel:  ? 0xffffffffa044e000
Oct 09 14:17:46 lp-sasha kernel:  do_one_initcall+0x48/0x1e0
Oct 09 14:17:46 lp-sasha kernel:  ? _cond_resched+0x11/0x60
Oct 09 14:17:46 lp-sasha kernel:  ? kmem_cache_alloc_trace+0x19c/0x1e0
Oct 09 14:17:46 lp-sasha kernel:  do_init_module+0x57/0x220
Oct 09 14:17:46 lp-sasha kernel:  __do_sys_finit_module+0xa0/0xe0
Oct 09 14:17:46 lp-sasha kernel:  do_syscall_64+0x33/0x40
Oct 09 14:17:46 lp-sasha kernel:  entry_SYSCALL_64_after_hwframe+0x44/0xa9
Oct 09 14:17:46 lp-sasha kernel: RIP: 0033:0x7fd01a060d5d
Oct 09 14:17:46 lp-sasha kernel: Code: 00 c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d e3 70 0c 00 f7 d8 64 89 01 48
Oct 09 14:17:46 lp-sasha kernel: RSP: 002b:00007ffc8ad38a98 EFLAGS: 00000246 ORIG_RAX: 0000000000000139
Oct 09 14:17:46 lp-sasha kernel: RAX: ffffffffffffffda RBX: 0000563f6e7fd530 RCX: 00007fd01a060d5d
Oct 09 14:17:46 lp-sasha kernel: RDX: 0000000000000000 RSI: 00007fd01a19f95d RDI: 000000000000000f
Oct 09 14:17:46 lp-sasha kernel: RBP: 0000000000020000 R08: 0000000000000000 R09: 0000000000000007
Oct 09 14:17:46 lp-sasha kernel: R10: 000000000000000f R11: 0000000000000246 R12: 00007fd01a19f95d
Oct 09 14:17:46 lp-sasha kernel: R13: 0000000000000000 R14: 0000563f6e7fbc10 R15: 0000563f6e7fd530
Oct 09 14:17:46 lp-sasha kernel: Modules linked in: nouveau(+) ttm xt_string xt_mark xt_LOG vgem v4l2_dv_timings uvcvideo ulpi udf ts_kmp ts_fsm ts_bm snd_aloop sil164 qat_dh895xccvf nf_nat_sip nf_nat_irc nf_nat_ftp nf_nat nf_log_ipv6 nf_log_ipv4 nf_log_common ltc2990 lcd intel_qat input_leds i2c_mux gspca_main videobuf2_vmalloc videobuf2_memops videobuf2_v4l2 videobuf2_common videodev mc drivetemp cuse fuse crc_itu_t coretemp ch7006 ath5k ath algif_hash
Oct 09 14:17:46 lp-sasha kernel: CR2: 0000000000000000
Oct 09 14:17:46 lp-sasha kernel: ---[ end trace 0ddafe218ad30017 ]---
Oct 09 14:17:46 lp-sasha kernel: RIP: 0010:nouveau_connector_detect_depth+0x71/0xc0 [nouveau]
Oct 09 14:17:46 lp-sasha kernel: Code: 0a 00 00 48 8b 49 48 c7 87 b8 00 00 00 06 00 00 00 80 b9 4d 0a 00 00 00 75 1e 83 fa 41 75 05 48 85 c0 75 29 8b 81 10 0d 00 00 <39> 06 7c 25 f6 81 14 0d 00 00 02 75 b7 c3 80 b9 0c 0d 00 00 00 75
Oct 09 14:17:46 lp-sasha kernel: RSP: 0018:ffffc9000028f8c0 EFLAGS: 00010297
Oct 09 14:17:46 lp-sasha kernel: RAX: 0000000000014c08 RBX: ffff8880369d4000 RCX: ffff8880369d3000
Oct 09 14:17:46 lp-sasha kernel: RDX: 0000000000000040 RSI: 0000000000000000 RDI: ffff8880369d4000
Oct 09 14:17:46 lp-sasha kernel: RBP: ffff88800601cc00 R08: ffff8880051da298 R09: ffffffff8226201a
Oct 09 14:17:46 lp-sasha kernel: R10: ffff88800469aa80 R11: ffff888004c84ff8 R12: 0000000000000000
Oct 09 14:17:46 lp-sasha kernel: R13: ffff8880051da000 R14: 0000000000002000 R15: 0000000000000003
Oct 09 14:17:46 lp-sasha kernel: FS:  00007fd0192b3440(0000) GS:ffff8880bc900000(0000) knlGS:0000000000000000
Oct 09 14:17:46 lp-sasha kernel: CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
Oct 09 14:17:46 lp-sasha kernel: CR2: 0000000000000000 CR3: 0000000004976000 CR4: 00000000000006e0

The disassembly:
Code: 0a 00 00 48 8b 49 48 c7 87 b8 00 00 00 06 00 00 00 80 b9 4d 0a 00 00 00 75 1e 83 fa 41 75 05 48 85 c0 75 29 8b 81 10 0d 00 00 <39> 06 7c 25 f6 81 14 0d 00 00 02 75 b7 c3 80 b9 0c 0d 00 00 00 75
All code
========
   0:   0a 00                   or     (%rax),%al
   2:   00 48 8b                add    %cl,-0x75(%rax)
   5:   49                      rex.WB
   6:   48 c7 87 b8 00 00 00    movq   $0x6,0xb8(%rdi)
   d:   06 00 00 00
  11:   80 b9 4d 0a 00 00 00    cmpb   $0x0,0xa4d(%rcx)
  18:   75 1e                   jne    0x38
  1a:   83 fa 41                cmp    $0x41,%edx
  1d:   75 05                   jne    0x24
  1f:   48 85 c0                test   %rax,%rax
  22:   75 29                   jne    0x4d
  24:   8b 81 10 0d 00 00       mov    0xd10(%rcx),%eax
  2a:*  39 06                   cmp    %eax,(%rsi)              <-- trapping instruction
  2c:   7c 25                   jl     0x53
  2e:   f6 81 14 0d 00 00 02    testb  $0x2,0xd14(%rcx)
  35:   75 b7                   jne    0xffffffffffffffee
  37:   c3                      retq
  38:   80 b9 0c 0d 00 00 00    cmpb   $0x0,0xd0c(%rcx)
  3f:   75                      .byte 0x75

Code starting with the faulting instruction
===========================================
   0:   39 06                   cmp    %eax,(%rsi)
   2:   7c 25                   jl     0x29
   4:   f6 81 14 0d 00 00 02    testb  $0x2,0xd14(%rcx)
   b:   75 b7                   jne    0xffffffffffffffc4
   d:   c3                      retq
   e:   80 b9 0c 0d 00 00 00    cmpb   $0x0,0xd0c(%rcx)
  15:   75                      .byte 0x75

objdump -SF --disassemble=nouveau_connector_detect_depth
[...]
        if (nv_connector->edid &&
   c85e1:       83 fa 41                cmp    $0x41,%edx
   c85e4:       75 05                   jne    c85eb <nouveau_connector_detect_depth+0x6b> (File Offset: 0xc866b)
   c85e6:       48 85 c0                test   %rax,%rax
   c85e9:       75 29                   jne    c8614 <nouveau_connector_detect_depth+0x94> (File Offset: 0xc8694)
            nv_connector->type == DCB_CONNECTOR_LVDS_SPWG)
                duallink = ((u8 *)nv_connector->edid)[121] == 2;
        else
                duallink = mode->clock >= bios->fp.duallink_transition_clk;

        if ((!duallink && (bios->fp.strapless_is_24bit & 1)) ||
   c85eb:       8b 81 10 0d 00 00       mov    0xd10(%rcx),%eax
   c85f1:       39 06                   cmp    %eax,(%rsi)
   c85f3:       7c 25                   jl     c861a <nouveau_connector_detect_depth+0x9a> (File Offset: 0xc869a)
            ( duallink && (bios->fp.strapless_is_24bit & 2)))
   c85f5:       f6 81 14 0d 00 00 02    testb  $0x2,0xd14(%rcx)
   c85fc:       75 b7                   jne    c85b5 <nouveau_connector_detect_depth+0x35> (File Offset: 0xc8635)
                connector->display_info.bpc = 8;
[...]

% scripts/faddr2line /lib/modules/5.9.0-rc8-next-20201009/kernel/drivers/gpu/drm/nouveau/nouveau.ko nouveau_connector_detect_depth+0x71/0xc0
nouveau_connector_detect_depth+0x71/0xc0:
nouveau_connector_detect_depth at /home/sasha/linux-next/drivers/gpu/drm/nouveau/nouveau_connector.c:891

It is actually line 889. See the disassembly below.
889                     duallink = mode->clock >= bios->fp.duallink_transition_clk;

The NULL pointer being dereferenced is mode.

Git bisect has identified the following commit as bad:
f28e32d drm/nouveau/kms: Don't change EDID when it hasn't actually changed

Here is the chain of events that causes the oops.
On entry to nouveau_connector_detect_lvds, edid is set to NULL.  The call
to nouveau_connector_detect sets nv_connector->edid to valid memory,
with status set to connector_status_connected and the flow of execution
branching to the out label.

The subsequent call to nouveau_connector_set_edid erronously clears
nv_connector->edid, via the local edid pointer which remains set to NULL.

Fix this by setting edid to the value of the just acquired
nv_connector->edid and executing the body of nouveau_connector_set_edid
only if nv_connector->edid and edid point to different memory addresses
thus preventing nv_connector->edid from being turned into a dangling
pointer.

Fixes: f28e32d ("drm/nouveau/kms: Don't change EDID when it hasn't actually changed")
Signed-off-by: Alexander Kapshuk <alexander.kapshuk@gmail.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
frank-w pushed a commit that referenced this issue Apr 9, 2021
If GPU components have failed to bind, shutdown callback would fail with
the following backtrace. Add safeguard check to stop that oops from
happening and allow the board to reboot.

[   66.617046] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
[   66.626066] Mem abort info:
[   66.628939]   ESR = 0x96000006
[   66.632088]   EC = 0x25: DABT (current EL), IL = 32 bits
[   66.637542]   SET = 0, FnV = 0
[   66.640688]   EA = 0, S1PTW = 0
[   66.643924] Data abort info:
[   66.646889]   ISV = 0, ISS = 0x00000006
[   66.650832]   CM = 0, WnR = 0
[   66.653890] user pgtable: 4k pages, 48-bit VAs, pgdp=0000000107f81000
[   66.660505] [0000000000000000] pgd=0000000100bb2003, p4d=0000000100bb2003, pud=0000000100897003, pmd=0000000000000000
[   66.671398] Internal error: Oops: 96000006 [#1] PREEMPT SMP
[   66.677115] Modules linked in:
[   66.680261] CPU: 6 PID: 352 Comm: reboot Not tainted 5.11.0-rc2-00309-g79e3faa756b2 #38
[   66.688473] Hardware name: Qualcomm Technologies, Inc. Robotics RB5 (DT)
[   66.695347] pstate: 60400005 (nZCv daif +PAN -UAO -TCO BTYPE=--)
[   66.701507] pc : msm_atomic_commit_tail+0x78/0x4e0
[   66.706437] lr : commit_tail+0xa4/0x184
[   66.710381] sp : ffff8000108f3af0
[   66.713791] x29: ffff8000108f3af0 x28: ffff418c44337000
[   66.719242] x27: 0000000000000000 x26: ffff418c40a24490
[   66.724693] x25: ffffd3a842a4f1a0 x24: 0000000000000008
[   66.730146] x23: ffffd3a84313f030 x22: ffff418c444ce000
[   66.735598] x21: ffff418c408a4980 x20: 0000000000000000
[   66.741049] x19: 0000000000000000 x18: ffff800010710fbc
[   66.746500] x17: 000000000000000c x16: 0000000000000001
[   66.751954] x15: 0000000000010008 x14: 0000000000000068
[   66.757405] x13: 0000000000000001 x12: 0000000000000000
[   66.762855] x11: 0000000000000001 x10: 00000000000009b0
[   66.768306] x9 : ffffd3a843192000 x8 : ffff418c44337000
[   66.773757] x7 : 0000000000000000 x6 : 00000000a401b34e
[   66.779210] x5 : 00ffffffffffffff x4 : 0000000000000000
[   66.784660] x3 : 0000000000000000 x2 : ffff418c444ce000
[   66.790111] x1 : ffffd3a841dce530 x0 : ffff418c444cf000
[   66.795563] Call trace:
[   66.798075]  msm_atomic_commit_tail+0x78/0x4e0
[   66.802633]  commit_tail+0xa4/0x184
[   66.806217]  drm_atomic_helper_commit+0x160/0x390
[   66.811051]  drm_atomic_commit+0x4c/0x60
[   66.815082]  drm_atomic_helper_disable_all+0x1f4/0x210
[   66.820355]  drm_atomic_helper_shutdown+0x80/0x130
[   66.825276]  msm_pdev_shutdown+0x14/0x20
[   66.829303]  platform_shutdown+0x28/0x40
[   66.833330]  device_shutdown+0x158/0x330
[   66.837357]  kernel_restart+0x40/0xa0
[   66.841122]  __do_sys_reboot+0x228/0x250
[   66.845148]  __arm64_sys_reboot+0x28/0x34
[   66.849264]  el0_svc_common.constprop.0+0x74/0x190
[   66.854187]  do_el0_svc+0x24/0x90
[   66.857595]  el0_svc+0x14/0x20
[   66.860739]  el0_sync_handler+0x1a4/0x1b0
[   66.864858]  el0_sync+0x174/0x180
[   66.868269] Code: 1ac020a0 2a000273 eb02007f 54ffff01 (f9400285)
[   66.874525] ---[ end trace 20dedb2a3229fec8 ]---

Fixes: 9d5cbf5 ("drm/msm: add shutdown support for display platform_driver")
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Fabio Estevam <festevam@gmail.com>
Signed-off-by: Rob Clark <robdclark@chromium.org>
frank-w pushed a commit that referenced this issue Apr 9, 2021
[ Upstream commit 623f279 ]

If GPU components have failed to bind, shutdown callback would fail with
the following backtrace. Add safeguard check to stop that oops from
happening and allow the board to reboot.

[   66.617046] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
[   66.626066] Mem abort info:
[   66.628939]   ESR = 0x96000006
[   66.632088]   EC = 0x25: DABT (current EL), IL = 32 bits
[   66.637542]   SET = 0, FnV = 0
[   66.640688]   EA = 0, S1PTW = 0
[   66.643924] Data abort info:
[   66.646889]   ISV = 0, ISS = 0x00000006
[   66.650832]   CM = 0, WnR = 0
[   66.653890] user pgtable: 4k pages, 48-bit VAs, pgdp=0000000107f81000
[   66.660505] [0000000000000000] pgd=0000000100bb2003, p4d=0000000100bb2003, pud=0000000100897003, pmd=0000000000000000
[   66.671398] Internal error: Oops: 96000006 [#1] PREEMPT SMP
[   66.677115] Modules linked in:
[   66.680261] CPU: 6 PID: 352 Comm: reboot Not tainted 5.11.0-rc2-00309-g79e3faa756b2 #38
[   66.688473] Hardware name: Qualcomm Technologies, Inc. Robotics RB5 (DT)
[   66.695347] pstate: 60400005 (nZCv daif +PAN -UAO -TCO BTYPE=--)
[   66.701507] pc : msm_atomic_commit_tail+0x78/0x4e0
[   66.706437] lr : commit_tail+0xa4/0x184
[   66.710381] sp : ffff8000108f3af0
[   66.713791] x29: ffff8000108f3af0 x28: ffff418c44337000
[   66.719242] x27: 0000000000000000 x26: ffff418c40a24490
[   66.724693] x25: ffffd3a842a4f1a0 x24: 0000000000000008
[   66.730146] x23: ffffd3a84313f030 x22: ffff418c444ce000
[   66.735598] x21: ffff418c408a4980 x20: 0000000000000000
[   66.741049] x19: 0000000000000000 x18: ffff800010710fbc
[   66.746500] x17: 000000000000000c x16: 0000000000000001
[   66.751954] x15: 0000000000010008 x14: 0000000000000068
[   66.757405] x13: 0000000000000001 x12: 0000000000000000
[   66.762855] x11: 0000000000000001 x10: 00000000000009b0
[   66.768306] x9 : ffffd3a843192000 x8 : ffff418c44337000
[   66.773757] x7 : 0000000000000000 x6 : 00000000a401b34e
[   66.779210] x5 : 00ffffffffffffff x4 : 0000000000000000
[   66.784660] x3 : 0000000000000000 x2 : ffff418c444ce000
[   66.790111] x1 : ffffd3a841dce530 x0 : ffff418c444cf000
[   66.795563] Call trace:
[   66.798075]  msm_atomic_commit_tail+0x78/0x4e0
[   66.802633]  commit_tail+0xa4/0x184
[   66.806217]  drm_atomic_helper_commit+0x160/0x390
[   66.811051]  drm_atomic_commit+0x4c/0x60
[   66.815082]  drm_atomic_helper_disable_all+0x1f4/0x210
[   66.820355]  drm_atomic_helper_shutdown+0x80/0x130
[   66.825276]  msm_pdev_shutdown+0x14/0x20
[   66.829303]  platform_shutdown+0x28/0x40
[   66.833330]  device_shutdown+0x158/0x330
[   66.837357]  kernel_restart+0x40/0xa0
[   66.841122]  __do_sys_reboot+0x228/0x250
[   66.845148]  __arm64_sys_reboot+0x28/0x34
[   66.849264]  el0_svc_common.constprop.0+0x74/0x190
[   66.854187]  do_el0_svc+0x24/0x90
[   66.857595]  el0_svc+0x14/0x20
[   66.860739]  el0_sync_handler+0x1a4/0x1b0
[   66.864858]  el0_sync+0x174/0x180
[   66.868269] Code: 1ac020a0 2a000273 eb02007f 54ffff01 (f9400285)
[   66.874525] ---[ end trace 20dedb2a3229fec8 ]---

Fixes: 9d5cbf5 ("drm/msm: add shutdown support for display platform_driver")
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Fabio Estevam <festevam@gmail.com>
Signed-off-by: Rob Clark <robdclark@chromium.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
frank-w pushed a commit that referenced this issue Apr 9, 2021
[ Upstream commit 623f279 ]

If GPU components have failed to bind, shutdown callback would fail with
the following backtrace. Add safeguard check to stop that oops from
happening and allow the board to reboot.

[   66.617046] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
[   66.626066] Mem abort info:
[   66.628939]   ESR = 0x96000006
[   66.632088]   EC = 0x25: DABT (current EL), IL = 32 bits
[   66.637542]   SET = 0, FnV = 0
[   66.640688]   EA = 0, S1PTW = 0
[   66.643924] Data abort info:
[   66.646889]   ISV = 0, ISS = 0x00000006
[   66.650832]   CM = 0, WnR = 0
[   66.653890] user pgtable: 4k pages, 48-bit VAs, pgdp=0000000107f81000
[   66.660505] [0000000000000000] pgd=0000000100bb2003, p4d=0000000100bb2003, pud=0000000100897003, pmd=0000000000000000
[   66.671398] Internal error: Oops: 96000006 [#1] PREEMPT SMP
[   66.677115] Modules linked in:
[   66.680261] CPU: 6 PID: 352 Comm: reboot Not tainted 5.11.0-rc2-00309-g79e3faa756b2 #38
[   66.688473] Hardware name: Qualcomm Technologies, Inc. Robotics RB5 (DT)
[   66.695347] pstate: 60400005 (nZCv daif +PAN -UAO -TCO BTYPE=--)
[   66.701507] pc : msm_atomic_commit_tail+0x78/0x4e0
[   66.706437] lr : commit_tail+0xa4/0x184
[   66.710381] sp : ffff8000108f3af0
[   66.713791] x29: ffff8000108f3af0 x28: ffff418c44337000
[   66.719242] x27: 0000000000000000 x26: ffff418c40a24490
[   66.724693] x25: ffffd3a842a4f1a0 x24: 0000000000000008
[   66.730146] x23: ffffd3a84313f030 x22: ffff418c444ce000
[   66.735598] x21: ffff418c408a4980 x20: 0000000000000000
[   66.741049] x19: 0000000000000000 x18: ffff800010710fbc
[   66.746500] x17: 000000000000000c x16: 0000000000000001
[   66.751954] x15: 0000000000010008 x14: 0000000000000068
[   66.757405] x13: 0000000000000001 x12: 0000000000000000
[   66.762855] x11: 0000000000000001 x10: 00000000000009b0
[   66.768306] x9 : ffffd3a843192000 x8 : ffff418c44337000
[   66.773757] x7 : 0000000000000000 x6 : 00000000a401b34e
[   66.779210] x5 : 00ffffffffffffff x4 : 0000000000000000
[   66.784660] x3 : 0000000000000000 x2 : ffff418c444ce000
[   66.790111] x1 : ffffd3a841dce530 x0 : ffff418c444cf000
[   66.795563] Call trace:
[   66.798075]  msm_atomic_commit_tail+0x78/0x4e0
[   66.802633]  commit_tail+0xa4/0x184
[   66.806217]  drm_atomic_helper_commit+0x160/0x390
[   66.811051]  drm_atomic_commit+0x4c/0x60
[   66.815082]  drm_atomic_helper_disable_all+0x1f4/0x210
[   66.820355]  drm_atomic_helper_shutdown+0x80/0x130
[   66.825276]  msm_pdev_shutdown+0x14/0x20
[   66.829303]  platform_shutdown+0x28/0x40
[   66.833330]  device_shutdown+0x158/0x330
[   66.837357]  kernel_restart+0x40/0xa0
[   66.841122]  __do_sys_reboot+0x228/0x250
[   66.845148]  __arm64_sys_reboot+0x28/0x34
[   66.849264]  el0_svc_common.constprop.0+0x74/0x190
[   66.854187]  do_el0_svc+0x24/0x90
[   66.857595]  el0_svc+0x14/0x20
[   66.860739]  el0_sync_handler+0x1a4/0x1b0
[   66.864858]  el0_sync+0x174/0x180
[   66.868269] Code: 1ac020a0 2a000273 eb02007f 54ffff01 (f9400285)
[   66.874525] ---[ end trace 20dedb2a3229fec8 ]---

Fixes: 9d5cbf5 ("drm/msm: add shutdown support for display platform_driver")
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Fabio Estevam <festevam@gmail.com>
Signed-off-by: Rob Clark <robdclark@chromium.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
frank-w pushed a commit that referenced this issue Apr 9, 2021
[ Upstream commit 623f279 ]

If GPU components have failed to bind, shutdown callback would fail with
the following backtrace. Add safeguard check to stop that oops from
happening and allow the board to reboot.

[   66.617046] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
[   66.626066] Mem abort info:
[   66.628939]   ESR = 0x96000006
[   66.632088]   EC = 0x25: DABT (current EL), IL = 32 bits
[   66.637542]   SET = 0, FnV = 0
[   66.640688]   EA = 0, S1PTW = 0
[   66.643924] Data abort info:
[   66.646889]   ISV = 0, ISS = 0x00000006
[   66.650832]   CM = 0, WnR = 0
[   66.653890] user pgtable: 4k pages, 48-bit VAs, pgdp=0000000107f81000
[   66.660505] [0000000000000000] pgd=0000000100bb2003, p4d=0000000100bb2003, pud=0000000100897003, pmd=0000000000000000
[   66.671398] Internal error: Oops: 96000006 [#1] PREEMPT SMP
[   66.677115] Modules linked in:
[   66.680261] CPU: 6 PID: 352 Comm: reboot Not tainted 5.11.0-rc2-00309-g79e3faa756b2 #38
[   66.688473] Hardware name: Qualcomm Technologies, Inc. Robotics RB5 (DT)
[   66.695347] pstate: 60400005 (nZCv daif +PAN -UAO -TCO BTYPE=--)
[   66.701507] pc : msm_atomic_commit_tail+0x78/0x4e0
[   66.706437] lr : commit_tail+0xa4/0x184
[   66.710381] sp : ffff8000108f3af0
[   66.713791] x29: ffff8000108f3af0 x28: ffff418c44337000
[   66.719242] x27: 0000000000000000 x26: ffff418c40a24490
[   66.724693] x25: ffffd3a842a4f1a0 x24: 0000000000000008
[   66.730146] x23: ffffd3a84313f030 x22: ffff418c444ce000
[   66.735598] x21: ffff418c408a4980 x20: 0000000000000000
[   66.741049] x19: 0000000000000000 x18: ffff800010710fbc
[   66.746500] x17: 000000000000000c x16: 0000000000000001
[   66.751954] x15: 0000000000010008 x14: 0000000000000068
[   66.757405] x13: 0000000000000001 x12: 0000000000000000
[   66.762855] x11: 0000000000000001 x10: 00000000000009b0
[   66.768306] x9 : ffffd3a843192000 x8 : ffff418c44337000
[   66.773757] x7 : 0000000000000000 x6 : 00000000a401b34e
[   66.779210] x5 : 00ffffffffffffff x4 : 0000000000000000
[   66.784660] x3 : 0000000000000000 x2 : ffff418c444ce000
[   66.790111] x1 : ffffd3a841dce530 x0 : ffff418c444cf000
[   66.795563] Call trace:
[   66.798075]  msm_atomic_commit_tail+0x78/0x4e0
[   66.802633]  commit_tail+0xa4/0x184
[   66.806217]  drm_atomic_helper_commit+0x160/0x390
[   66.811051]  drm_atomic_commit+0x4c/0x60
[   66.815082]  drm_atomic_helper_disable_all+0x1f4/0x210
[   66.820355]  drm_atomic_helper_shutdown+0x80/0x130
[   66.825276]  msm_pdev_shutdown+0x14/0x20
[   66.829303]  platform_shutdown+0x28/0x40
[   66.833330]  device_shutdown+0x158/0x330
[   66.837357]  kernel_restart+0x40/0xa0
[   66.841122]  __do_sys_reboot+0x228/0x250
[   66.845148]  __arm64_sys_reboot+0x28/0x34
[   66.849264]  el0_svc_common.constprop.0+0x74/0x190
[   66.854187]  do_el0_svc+0x24/0x90
[   66.857595]  el0_svc+0x14/0x20
[   66.860739]  el0_sync_handler+0x1a4/0x1b0
[   66.864858]  el0_sync+0x174/0x180
[   66.868269] Code: 1ac020a0 2a000273 eb02007f 54ffff01 (f9400285)
[   66.874525] ---[ end trace 20dedb2a3229fec8 ]---

Fixes: 9d5cbf5 ("drm/msm: add shutdown support for display platform_driver")
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Fabio Estevam <festevam@gmail.com>
Signed-off-by: Rob Clark <robdclark@chromium.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
frank-w pushed a commit that referenced this issue May 23, 2022
This patch fixes a memory corruption that occurred in the
nand_scan() path for Hynix nand device.

On boot, for Hynix nand device will panic at a weird place:
| Unable to handle kernel NULL pointer dereference at virtual
  address 00000070
| [00000070] *pgd=00000000
| Internal error: Oops: 5 [#1] PREEMPT SMP ARM
| Modules linked in:
| CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.17.0-01473-g13ae1769cfb0
  #38
| Hardware name: Generic DT based system
| PC is at nandc_set_reg+0x8/0x1c
| LR is at qcom_nandc_command+0x20c/0x5d0
| pc : [<c088b74c>]    lr : [<c088d9c8>]    psr: 00000113
| sp : c14adc50  ip : c14ee208  fp : c0cc970c
| r10: 000000a3  r9 : 00000000  r8 : 00000040
| r7 : c16f6a00  r6 : 00000090  r5 : 00000004  r4 :c14ee040
| r3 : 00000000  r2 : 0000000b  r1 : 00000000  r0 :c14ee040
| Flags: nzcv  IRQs on  FIQs on  Mode SVC_32  ISA ARM Segment none
| Control: 10c5387d  Table: 8020406a  DAC: 00000051
| Register r0 information: slab kmalloc-2k start c14ee000 pointer offset
  64 size 2048
| Process swapper/0 (pid: 1, stack limit = 0x(ptrval))
| nandc_set_reg from qcom_nandc_command+0x20c/0x5d0
| qcom_nandc_command from nand_readid_op+0x198/0x1e8
| nand_readid_op from hynix_nand_has_valid_jedecid+0x30/0x78
| hynix_nand_has_valid_jedecid from hynix_nand_init+0xb8/0x454
| hynix_nand_init from nand_scan_with_ids+0xa30/0x14a8
| nand_scan_with_ids from qcom_nandc_probe+0x648/0x7b0
| qcom_nandc_probe from platform_probe+0x58/0xac

The problem is that the nand_scan()'s qcom_nand_attach_chip callback
is updating the nandc->max_cwperpage from 1 to 4 or 8 based on page size.
This causes the sg_init_table of clear_bam_transaction() in the driver's
qcom_nandc_command() to memset much more than what was initially
allocated by alloc_bam_transaction().

This patch will update nandc->max_cwperpage 1 to 4 or 8 based on page
size in qcom_nand_attach_chip call back after freeing the previously
allocated memory for bam txn as per nandc->max_cwperpage = 1 and then
again allocating bam txn as per nandc->max_cwperpage = 4 or 8 based on
page size in qcom_nand_attach_chip call back itself.

Cc: stable@vger.kernel.org
Fixes: 6a3cec6 ("mtd: rawnand: qcom: convert driver to nand_scan()")
Reported-by: Konrad Dybcio <konrad.dybcio@somainline.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Co-developed-by: Sricharan R <quic_srichara@quicinc.com>
Signed-off-by: Sricharan R <quic_srichara@quicinc.com>
Signed-off-by: Md Sadre Alam <quic_mdalam@quicinc.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/1650268107-5363-1-git-send-email-quic_mdalam@quicinc.com
frank-w pushed a commit that referenced this issue May 25, 2022
commit ba7542e upstream.

This patch fixes a memory corruption that occurred in the
nand_scan() path for Hynix nand device.

On boot, for Hynix nand device will panic at a weird place:
| Unable to handle kernel NULL pointer dereference at virtual
  address 00000070
| [00000070] *pgd=00000000
| Internal error: Oops: 5 [#1] PREEMPT SMP ARM
| Modules linked in:
| CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.17.0-01473-g13ae1769cfb0
  #38
| Hardware name: Generic DT based system
| PC is at nandc_set_reg+0x8/0x1c
| LR is at qcom_nandc_command+0x20c/0x5d0
| pc : [<c088b74c>]    lr : [<c088d9c8>]    psr: 00000113
| sp : c14adc50  ip : c14ee208  fp : c0cc970c
| r10: 000000a3  r9 : 00000000  r8 : 00000040
| r7 : c16f6a00  r6 : 00000090  r5 : 00000004  r4 :c14ee040
| r3 : 00000000  r2 : 0000000b  r1 : 00000000  r0 :c14ee040
| Flags: nzcv  IRQs on  FIQs on  Mode SVC_32  ISA ARM Segment none
| Control: 10c5387d  Table: 8020406a  DAC: 00000051
| Register r0 information: slab kmalloc-2k start c14ee000 pointer offset
  64 size 2048
| Process swapper/0 (pid: 1, stack limit = 0x(ptrval))
| nandc_set_reg from qcom_nandc_command+0x20c/0x5d0
| qcom_nandc_command from nand_readid_op+0x198/0x1e8
| nand_readid_op from hynix_nand_has_valid_jedecid+0x30/0x78
| hynix_nand_has_valid_jedecid from hynix_nand_init+0xb8/0x454
| hynix_nand_init from nand_scan_with_ids+0xa30/0x14a8
| nand_scan_with_ids from qcom_nandc_probe+0x648/0x7b0
| qcom_nandc_probe from platform_probe+0x58/0xac

The problem is that the nand_scan()'s qcom_nand_attach_chip callback
is updating the nandc->max_cwperpage from 1 to 4 or 8 based on page size.
This causes the sg_init_table of clear_bam_transaction() in the driver's
qcom_nandc_command() to memset much more than what was initially
allocated by alloc_bam_transaction().

This patch will update nandc->max_cwperpage 1 to 4 or 8 based on page
size in qcom_nand_attach_chip call back after freeing the previously
allocated memory for bam txn as per nandc->max_cwperpage = 1 and then
again allocating bam txn as per nandc->max_cwperpage = 4 or 8 based on
page size in qcom_nand_attach_chip call back itself.

Cc: stable@vger.kernel.org
Fixes: 6a3cec6 ("mtd: rawnand: qcom: convert driver to nand_scan()")
Reported-by: Konrad Dybcio <konrad.dybcio@somainline.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Co-developed-by: Sricharan R <quic_srichara@quicinc.com>
Signed-off-by: Sricharan R <quic_srichara@quicinc.com>
Signed-off-by: Md Sadre Alam <quic_mdalam@quicinc.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/1650268107-5363-1-git-send-email-quic_mdalam@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
frank-w pushed a commit that referenced this issue Aug 7, 2022
commit d02ba2a upstream.

pppol2tp_release uses call_rcu to put the final ref on its socket. But
the session object doesn't hold a ref on the session socket so may be
freed while the pppol2tp_put_sk RCU callback is scheduled. Fix this by
having the session hold a ref on its socket until the session is
destroyed. It is this ref that is dropped via call_rcu.

Sessions are also deleted via l2tp_tunnel_closeall. This must now also put
the final ref via call_rcu. So move the call_rcu call site into
pppol2tp_session_close so that this happens in both destroy paths. A
common destroy path should really be implemented, perhaps with
l2tp_tunnel_closeall calling l2tp_session_delete like pppol2tp_release
does, but this will be looked at later.

ODEBUG: activate active (active state 1) object type: rcu_head hint:           (null)
WARNING: CPU: 3 PID: 13407 at lib/debugobjects.c:291 debug_print_object+0x166/0x220
Modules linked in:
CPU: 3 PID: 13407 Comm: syzbot_19c09769 Not tainted 4.16.0-rc2+ #38
Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
RIP: 0010:debug_print_object+0x166/0x220
RSP: 0018:ffff880013647a00 EFLAGS: 00010082
RAX: dffffc0000000008 RBX: 0000000000000003 RCX: ffffffff814d3333
RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff88001a59f6d0
RBP: ffff880013647a40 R08: 0000000000000000 R09: 0000000000000001
R10: ffff8800136479a8 R11: 0000000000000000 R12: 0000000000000001
R13: ffffffff86161420 R14: ffffffff85648b60 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff88001a580000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020e77000 CR3: 0000000006022000 CR4: 00000000000006e0
Call Trace:
 debug_object_activate+0x38b/0x530
 ? debug_object_assert_init+0x3b0/0x3b0
 ? __mutex_unlock_slowpath+0x85/0x8b0
 ? pppol2tp_session_destruct+0x110/0x110
 __call_rcu.constprop.66+0x39/0x890
 ? __call_rcu.constprop.66+0x39/0x890
 call_rcu_sched+0x17/0x20
 pppol2tp_release+0x2c7/0x440
 ? fcntl_setlk+0xca0/0xca0
 ? sock_alloc_file+0x340/0x340
 sock_release+0x92/0x1e0
 sock_close+0x1b/0x20
 __fput+0x296/0x6e0
 ____fput+0x1a/0x20
 task_work_run+0x127/0x1a0
 do_exit+0x7f9/0x2ce0
 ? SYSC_connect+0x212/0x310
 ? mm_update_next_owner+0x690/0x690
 ? up_read+0x1f/0x40
 ? __do_page_fault+0x3c8/0xca0
 do_group_exit+0x10d/0x330
 ? do_group_exit+0x330/0x330
 SyS_exit_group+0x22/0x30
 do_syscall_64+0x1e0/0x730
 ? trace_hardirqs_off_thunk+0x1a/0x1c
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x7f362e471259
RSP: 002b:00007ffe389abe08 EFLAGS: 00000202 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f362e471259
RDX: 00007f362e471259 RSI: 000000000000002e RDI: 0000000000000000
RBP: 00007ffe389abe30 R08: 0000000000000000 R09: 00007f362e944270
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000400b60
R13: 00007ffe389abf50 R14: 0000000000000000 R15: 0000000000000000
Code: 8d 3c dd a0 8f 64 85 48 89 fa 48 c1 ea 03 80 3c 02 00 75 7b 48 8b 14 dd a0 8f 64 85 4c 89 f6 48 c7 c7 20 85 64 85 e
8 2a 55 14 ff <0f> 0b 83 05 ad 2a 68 04 01 48 83 c4 18 5b 41 5c 41 5d 41 5e 41

Fixes: ee40fb2 ("l2tp: protect sock pointer of struct pppol2tp_session with RCU")
Signed-off-by: James Chapman <jchapman@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Cc: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
frank-w pushed a commit that referenced this issue Mar 18, 2023
commit c2dbe32 upstream.

If a non-root cgroup gets removed when there is a thread that registered
trigger and is polling on a pressure file within the cgroup, the polling
waitqueue gets freed in the following path:

 do_rmdir
   cgroup_rmdir
     kernfs_drain_open_files
       cgroup_file_release
         cgroup_pressure_release
           psi_trigger_destroy

However, the polling thread still has a reference to the pressure file and
will access the freed waitqueue when the file is closed or upon exit:

 fput
   ep_eventpoll_release
     ep_free
       ep_remove_wait_queue
         remove_wait_queue

This results in use-after-free as pasted below.

The fundamental problem here is that cgroup_file_release() (and
consequently waitqueue's lifetime) is not tied to the file's real lifetime.
Using wake_up_pollfree() here might be less than ideal, but it is in line
with the comment at commit 42288cb ("wait: add wake_up_pollfree()")
since the waitqueue's lifetime is not tied to file's one and can be
considered as another special case. While this would be fixable by somehow
making cgroup_file_release() be tied to the fput(), it would require
sizable refactoring at cgroups or higher layer which might be more
justifiable if we identify more cases like this.

  BUG: KASAN: use-after-free in _raw_spin_lock_irqsave+0x60/0xc0
  Write of size 4 at addr ffff88810e625328 by task a.out/4404

	CPU: 19 PID: 4404 Comm: a.out Not tainted 6.2.0-rc6 #38
	Hardware name: Amazon EC2 c5a.8xlarge/, BIOS 1.0 10/16/2017
	Call Trace:
	<TASK>
	dump_stack_lvl+0x73/0xa0
	print_report+0x16c/0x4e0
	kasan_report+0xc3/0xf0
	kasan_check_range+0x2d2/0x310
	_raw_spin_lock_irqsave+0x60/0xc0
	remove_wait_queue+0x1a/0xa0
	ep_free+0x12c/0x170
	ep_eventpoll_release+0x26/0x30
	__fput+0x202/0x400
	task_work_run+0x11d/0x170
	do_exit+0x495/0x1130
	do_group_exit+0x100/0x100
	get_signal+0xd67/0xde0
	arch_do_signal_or_restart+0x2a/0x2b0
	exit_to_user_mode_prepare+0x94/0x100
	syscall_exit_to_user_mode+0x20/0x40
	do_syscall_64+0x52/0x90
	entry_SYSCALL_64_after_hwframe+0x63/0xcd
	</TASK>

 Allocated by task 4404:

	kasan_set_track+0x3d/0x60
	__kasan_kmalloc+0x85/0x90
	psi_trigger_create+0x113/0x3e0
	pressure_write+0x146/0x2e0
	cgroup_file_write+0x11c/0x250
	kernfs_fop_write_iter+0x186/0x220
	vfs_write+0x3d8/0x5c0
	ksys_write+0x90/0x110
	do_syscall_64+0x43/0x90
	entry_SYSCALL_64_after_hwframe+0x63/0xcd

 Freed by task 4407:

	kasan_set_track+0x3d/0x60
	kasan_save_free_info+0x27/0x40
	____kasan_slab_free+0x11d/0x170
	slab_free_freelist_hook+0x87/0x150
	__kmem_cache_free+0xcb/0x180
	psi_trigger_destroy+0x2e8/0x310
	cgroup_file_release+0x4f/0xb0
	kernfs_drain_open_files+0x165/0x1f0
	kernfs_drain+0x162/0x1a0
	__kernfs_remove+0x1fb/0x310
	kernfs_remove_by_name_ns+0x95/0xe0
	cgroup_addrm_files+0x67f/0x700
	cgroup_destroy_locked+0x283/0x3c0
	cgroup_rmdir+0x29/0x100
	kernfs_iop_rmdir+0xd1/0x140
	vfs_rmdir+0xfe/0x240
	do_rmdir+0x13d/0x280
	__x64_sys_rmdir+0x2c/0x30
	do_syscall_64+0x43/0x90
	entry_SYSCALL_64_after_hwframe+0x63/0xcd

Fixes: 0e94682 ("psi: introduce psi monitor")
Signed-off-by: Munehisa Kamata <kamatam@amazon.com>
Signed-off-by: Mengchi Cheng <mengcc@amazon.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Suren Baghdasaryan <surenb@google.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/lkml/20230106224859.4123476-1-kamatam@amazon.com/
Link: https://lore.kernel.org/r/20230214212705.4058045-1-kamatam@amazon.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
frank-w pushed a commit that referenced this issue Mar 18, 2023
commit c2dbe32 upstream.

If a non-root cgroup gets removed when there is a thread that registered
trigger and is polling on a pressure file within the cgroup, the polling
waitqueue gets freed in the following path:

 do_rmdir
   cgroup_rmdir
     kernfs_drain_open_files
       cgroup_file_release
         cgroup_pressure_release
           psi_trigger_destroy

However, the polling thread still has a reference to the pressure file and
will access the freed waitqueue when the file is closed or upon exit:

 fput
   ep_eventpoll_release
     ep_free
       ep_remove_wait_queue
         remove_wait_queue

This results in use-after-free as pasted below.

The fundamental problem here is that cgroup_file_release() (and
consequently waitqueue's lifetime) is not tied to the file's real lifetime.
Using wake_up_pollfree() here might be less than ideal, but it is in line
with the comment at commit 42288cb ("wait: add wake_up_pollfree()")
since the waitqueue's lifetime is not tied to file's one and can be
considered as another special case. While this would be fixable by somehow
making cgroup_file_release() be tied to the fput(), it would require
sizable refactoring at cgroups or higher layer which might be more
justifiable if we identify more cases like this.

  BUG: KASAN: use-after-free in _raw_spin_lock_irqsave+0x60/0xc0
  Write of size 4 at addr ffff88810e625328 by task a.out/4404

	CPU: 19 PID: 4404 Comm: a.out Not tainted 6.2.0-rc6 #38
	Hardware name: Amazon EC2 c5a.8xlarge/, BIOS 1.0 10/16/2017
	Call Trace:
	<TASK>
	dump_stack_lvl+0x73/0xa0
	print_report+0x16c/0x4e0
	kasan_report+0xc3/0xf0
	kasan_check_range+0x2d2/0x310
	_raw_spin_lock_irqsave+0x60/0xc0
	remove_wait_queue+0x1a/0xa0
	ep_free+0x12c/0x170
	ep_eventpoll_release+0x26/0x30
	__fput+0x202/0x400
	task_work_run+0x11d/0x170
	do_exit+0x495/0x1130
	do_group_exit+0x100/0x100
	get_signal+0xd67/0xde0
	arch_do_signal_or_restart+0x2a/0x2b0
	exit_to_user_mode_prepare+0x94/0x100
	syscall_exit_to_user_mode+0x20/0x40
	do_syscall_64+0x52/0x90
	entry_SYSCALL_64_after_hwframe+0x63/0xcd
	</TASK>

 Allocated by task 4404:

	kasan_set_track+0x3d/0x60
	__kasan_kmalloc+0x85/0x90
	psi_trigger_create+0x113/0x3e0
	pressure_write+0x146/0x2e0
	cgroup_file_write+0x11c/0x250
	kernfs_fop_write_iter+0x186/0x220
	vfs_write+0x3d8/0x5c0
	ksys_write+0x90/0x110
	do_syscall_64+0x43/0x90
	entry_SYSCALL_64_after_hwframe+0x63/0xcd

 Freed by task 4407:

	kasan_set_track+0x3d/0x60
	kasan_save_free_info+0x27/0x40
	____kasan_slab_free+0x11d/0x170
	slab_free_freelist_hook+0x87/0x150
	__kmem_cache_free+0xcb/0x180
	psi_trigger_destroy+0x2e8/0x310
	cgroup_file_release+0x4f/0xb0
	kernfs_drain_open_files+0x165/0x1f0
	kernfs_drain+0x162/0x1a0
	__kernfs_remove+0x1fb/0x310
	kernfs_remove_by_name_ns+0x95/0xe0
	cgroup_addrm_files+0x67f/0x700
	cgroup_destroy_locked+0x283/0x3c0
	cgroup_rmdir+0x29/0x100
	kernfs_iop_rmdir+0xd1/0x140
	vfs_rmdir+0xfe/0x240
	do_rmdir+0x13d/0x280
	__x64_sys_rmdir+0x2c/0x30
	do_syscall_64+0x43/0x90
	entry_SYSCALL_64_after_hwframe+0x63/0xcd

Fixes: 0e94682 ("psi: introduce psi monitor")
Signed-off-by: Munehisa Kamata <kamatam@amazon.com>
Signed-off-by: Mengchi Cheng <mengcc@amazon.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Suren Baghdasaryan <surenb@google.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/lkml/20230106224859.4123476-1-kamatam@amazon.com/
Link: https://lore.kernel.org/r/20230214212705.4058045-1-kamatam@amazon.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
frank-w pushed a commit that referenced this issue Mar 18, 2023
commit c2dbe32 upstream.

If a non-root cgroup gets removed when there is a thread that registered
trigger and is polling on a pressure file within the cgroup, the polling
waitqueue gets freed in the following path:

 do_rmdir
   cgroup_rmdir
     kernfs_drain_open_files
       cgroup_file_release
         cgroup_pressure_release
           psi_trigger_destroy

However, the polling thread still has a reference to the pressure file and
will access the freed waitqueue when the file is closed or upon exit:

 fput
   ep_eventpoll_release
     ep_free
       ep_remove_wait_queue
         remove_wait_queue

This results in use-after-free as pasted below.

The fundamental problem here is that cgroup_file_release() (and
consequently waitqueue's lifetime) is not tied to the file's real lifetime.
Using wake_up_pollfree() here might be less than ideal, but it is in line
with the comment at commit 42288cb ("wait: add wake_up_pollfree()")
since the waitqueue's lifetime is not tied to file's one and can be
considered as another special case. While this would be fixable by somehow
making cgroup_file_release() be tied to the fput(), it would require
sizable refactoring at cgroups or higher layer which might be more
justifiable if we identify more cases like this.

  BUG: KASAN: use-after-free in _raw_spin_lock_irqsave+0x60/0xc0
  Write of size 4 at addr ffff88810e625328 by task a.out/4404

	CPU: 19 PID: 4404 Comm: a.out Not tainted 6.2.0-rc6 #38
	Hardware name: Amazon EC2 c5a.8xlarge/, BIOS 1.0 10/16/2017
	Call Trace:
	<TASK>
	dump_stack_lvl+0x73/0xa0
	print_report+0x16c/0x4e0
	kasan_report+0xc3/0xf0
	kasan_check_range+0x2d2/0x310
	_raw_spin_lock_irqsave+0x60/0xc0
	remove_wait_queue+0x1a/0xa0
	ep_free+0x12c/0x170
	ep_eventpoll_release+0x26/0x30
	__fput+0x202/0x400
	task_work_run+0x11d/0x170
	do_exit+0x495/0x1130
	do_group_exit+0x100/0x100
	get_signal+0xd67/0xde0
	arch_do_signal_or_restart+0x2a/0x2b0
	exit_to_user_mode_prepare+0x94/0x100
	syscall_exit_to_user_mode+0x20/0x40
	do_syscall_64+0x52/0x90
	entry_SYSCALL_64_after_hwframe+0x63/0xcd
	</TASK>

 Allocated by task 4404:

	kasan_set_track+0x3d/0x60
	__kasan_kmalloc+0x85/0x90
	psi_trigger_create+0x113/0x3e0
	pressure_write+0x146/0x2e0
	cgroup_file_write+0x11c/0x250
	kernfs_fop_write_iter+0x186/0x220
	vfs_write+0x3d8/0x5c0
	ksys_write+0x90/0x110
	do_syscall_64+0x43/0x90
	entry_SYSCALL_64_after_hwframe+0x63/0xcd

 Freed by task 4407:

	kasan_set_track+0x3d/0x60
	kasan_save_free_info+0x27/0x40
	____kasan_slab_free+0x11d/0x170
	slab_free_freelist_hook+0x87/0x150
	__kmem_cache_free+0xcb/0x180
	psi_trigger_destroy+0x2e8/0x310
	cgroup_file_release+0x4f/0xb0
	kernfs_drain_open_files+0x165/0x1f0
	kernfs_drain+0x162/0x1a0
	__kernfs_remove+0x1fb/0x310
	kernfs_remove_by_name_ns+0x95/0xe0
	cgroup_addrm_files+0x67f/0x700
	cgroup_destroy_locked+0x283/0x3c0
	cgroup_rmdir+0x29/0x100
	kernfs_iop_rmdir+0xd1/0x140
	vfs_rmdir+0xfe/0x240
	do_rmdir+0x13d/0x280
	__x64_sys_rmdir+0x2c/0x30
	do_syscall_64+0x43/0x90
	entry_SYSCALL_64_after_hwframe+0x63/0xcd

Fixes: 0e94682 ("psi: introduce psi monitor")
Signed-off-by: Munehisa Kamata <kamatam@amazon.com>
Signed-off-by: Mengchi Cheng <mengcc@amazon.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Suren Baghdasaryan <surenb@google.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/lkml/20230106224859.4123476-1-kamatam@amazon.com/
Link: https://lore.kernel.org/r/20230214212705.4058045-1-kamatam@amazon.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
frank-w pushed a commit that referenced this issue Mar 18, 2023
commit c2dbe32 upstream.

If a non-root cgroup gets removed when there is a thread that registered
trigger and is polling on a pressure file within the cgroup, the polling
waitqueue gets freed in the following path:

 do_rmdir
   cgroup_rmdir
     kernfs_drain_open_files
       cgroup_file_release
         cgroup_pressure_release
           psi_trigger_destroy

However, the polling thread still has a reference to the pressure file and
will access the freed waitqueue when the file is closed or upon exit:

 fput
   ep_eventpoll_release
     ep_free
       ep_remove_wait_queue
         remove_wait_queue

This results in use-after-free as pasted below.

The fundamental problem here is that cgroup_file_release() (and
consequently waitqueue's lifetime) is not tied to the file's real lifetime.
Using wake_up_pollfree() here might be less than ideal, but it is in line
with the comment at commit 42288cb ("wait: add wake_up_pollfree()")
since the waitqueue's lifetime is not tied to file's one and can be
considered as another special case. While this would be fixable by somehow
making cgroup_file_release() be tied to the fput(), it would require
sizable refactoring at cgroups or higher layer which might be more
justifiable if we identify more cases like this.

  BUG: KASAN: use-after-free in _raw_spin_lock_irqsave+0x60/0xc0
  Write of size 4 at addr ffff88810e625328 by task a.out/4404

	CPU: 19 PID: 4404 Comm: a.out Not tainted 6.2.0-rc6 #38
	Hardware name: Amazon EC2 c5a.8xlarge/, BIOS 1.0 10/16/2017
	Call Trace:
	<TASK>
	dump_stack_lvl+0x73/0xa0
	print_report+0x16c/0x4e0
	kasan_report+0xc3/0xf0
	kasan_check_range+0x2d2/0x310
	_raw_spin_lock_irqsave+0x60/0xc0
	remove_wait_queue+0x1a/0xa0
	ep_free+0x12c/0x170
	ep_eventpoll_release+0x26/0x30
	__fput+0x202/0x400
	task_work_run+0x11d/0x170
	do_exit+0x495/0x1130
	do_group_exit+0x100/0x100
	get_signal+0xd67/0xde0
	arch_do_signal_or_restart+0x2a/0x2b0
	exit_to_user_mode_prepare+0x94/0x100
	syscall_exit_to_user_mode+0x20/0x40
	do_syscall_64+0x52/0x90
	entry_SYSCALL_64_after_hwframe+0x63/0xcd
	</TASK>

 Allocated by task 4404:

	kasan_set_track+0x3d/0x60
	__kasan_kmalloc+0x85/0x90
	psi_trigger_create+0x113/0x3e0
	pressure_write+0x146/0x2e0
	cgroup_file_write+0x11c/0x250
	kernfs_fop_write_iter+0x186/0x220
	vfs_write+0x3d8/0x5c0
	ksys_write+0x90/0x110
	do_syscall_64+0x43/0x90
	entry_SYSCALL_64_after_hwframe+0x63/0xcd

 Freed by task 4407:

	kasan_set_track+0x3d/0x60
	kasan_save_free_info+0x27/0x40
	____kasan_slab_free+0x11d/0x170
	slab_free_freelist_hook+0x87/0x150
	__kmem_cache_free+0xcb/0x180
	psi_trigger_destroy+0x2e8/0x310
	cgroup_file_release+0x4f/0xb0
	kernfs_drain_open_files+0x165/0x1f0
	kernfs_drain+0x162/0x1a0
	__kernfs_remove+0x1fb/0x310
	kernfs_remove_by_name_ns+0x95/0xe0
	cgroup_addrm_files+0x67f/0x700
	cgroup_destroy_locked+0x283/0x3c0
	cgroup_rmdir+0x29/0x100
	kernfs_iop_rmdir+0xd1/0x140
	vfs_rmdir+0xfe/0x240
	do_rmdir+0x13d/0x280
	__x64_sys_rmdir+0x2c/0x30
	do_syscall_64+0x43/0x90
	entry_SYSCALL_64_after_hwframe+0x63/0xcd

Fixes: 0e94682 ("psi: introduce psi monitor")
Signed-off-by: Munehisa Kamata <kamatam@amazon.com>
Signed-off-by: Mengchi Cheng <mengcc@amazon.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Suren Baghdasaryan <surenb@google.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/lkml/20230106224859.4123476-1-kamatam@amazon.com/
Link: https://lore.kernel.org/r/20230214212705.4058045-1-kamatam@amazon.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
frank-w pushed a commit that referenced this issue Aug 31, 2023
…tect_depth

commit 630f512 upstream.

This oops manifests itself on the following hardware:
01:00.0 VGA compatible controller: NVIDIA Corporation G98M [GeForce G 103M] (rev a1)

Oct 09 14:17:46 lp-sasha kernel: BUG: kernel NULL pointer dereference, address: 0000000000000000
Oct 09 14:17:46 lp-sasha kernel: #PF: supervisor read access in kernel mode
Oct 09 14:17:46 lp-sasha kernel: #PF: error_code(0x0000) - not-present page
Oct 09 14:17:46 lp-sasha kernel: PGD 0 P4D 0
Oct 09 14:17:46 lp-sasha kernel: Oops: 0000 [#1] SMP PTI
Oct 09 14:17:46 lp-sasha kernel: CPU: 1 PID: 191 Comm: systemd-udevd Not tainted 5.9.0-rc8-next-20201009 #38
Oct 09 14:17:46 lp-sasha kernel: Hardware name: Hewlett-Packard Compaq Presario CQ61 Notebook PC/306A, BIOS F.03 03/23/2009
Oct 09 14:17:46 lp-sasha kernel: RIP: 0010:nouveau_connector_detect_depth+0x71/0xc0 [nouveau]
Oct 09 14:17:46 lp-sasha kernel: Code: 0a 00 00 48 8b 49 48 c7 87 b8 00 00 00 06 00 00 00 80 b9 4d 0a 00 00 00 75 1e 83 fa 41 75 05 48 85 c0 75 29 8b 81 10 0d 00 00 <39> 06 7c 25 f6 81 14 0d 00 00 02 75 b7 c3 80 b9 0c 0d 00 00 00 75
Oct 09 14:17:46 lp-sasha kernel: RSP: 0018:ffffc9000028f8c0 EFLAGS: 00010297
Oct 09 14:17:46 lp-sasha kernel: RAX: 0000000000014c08 RBX: ffff8880369d4000 RCX: ffff8880369d3000
Oct 09 14:17:46 lp-sasha kernel: RDX: 0000000000000040 RSI: 0000000000000000 RDI: ffff8880369d4000
Oct 09 14:17:46 lp-sasha kernel: RBP: ffff88800601cc00 R08: ffff8880051da298 R09: ffffffff8226201a
Oct 09 14:17:46 lp-sasha kernel: R10: ffff88800469aa80 R11: ffff888004c84ff8 R12: 0000000000000000
Oct 09 14:17:46 lp-sasha kernel: R13: ffff8880051da000 R14: 0000000000002000 R15: 0000000000000003
Oct 09 14:17:46 lp-sasha kernel: FS:  00007fd0192b3440(0000) GS:ffff8880bc900000(0000) knlGS:0000000000000000
Oct 09 14:17:46 lp-sasha kernel: CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
Oct 09 14:17:46 lp-sasha kernel: CR2: 0000000000000000 CR3: 0000000004976000 CR4: 00000000000006e0
Oct 09 14:17:46 lp-sasha kernel: Call Trace:
Oct 09 14:17:46 lp-sasha kernel:  nouveau_connector_get_modes+0x1e6/0x240 [nouveau]
Oct 09 14:17:46 lp-sasha kernel:  ? kfree+0xb9/0x240
Oct 09 14:17:46 lp-sasha kernel:  ? drm_connector_list_iter_next+0x7c/0xa0
Oct 09 14:17:46 lp-sasha kernel:  drm_helper_probe_single_connector_modes+0x1ba/0x7c0
Oct 09 14:17:46 lp-sasha kernel:  drm_client_modeset_probe+0x27e/0x1360
Oct 09 14:17:46 lp-sasha kernel:  ? nvif_object_sclass_put+0xc/0x20 [nouveau]
Oct 09 14:17:46 lp-sasha kernel:  ? nouveau_cli_init+0x3cc/0x440 [nouveau]
Oct 09 14:17:46 lp-sasha kernel:  ? ktime_get_mono_fast_ns+0x49/0xa0
Oct 09 14:17:46 lp-sasha kernel:  ? nouveau_drm_open+0x4e/0x180 [nouveau]
Oct 09 14:17:46 lp-sasha kernel:  __drm_fb_helper_initial_config_and_unlock+0x3f/0x4a0
Oct 09 14:17:46 lp-sasha kernel:  ? drm_file_alloc+0x18f/0x260
Oct 09 14:17:46 lp-sasha kernel:  ? mutex_lock+0x9/0x40
Oct 09 14:17:46 lp-sasha kernel:  ? drm_client_init+0x110/0x160
Oct 09 14:17:46 lp-sasha kernel:  nouveau_fbcon_init+0x14d/0x1c0 [nouveau]
Oct 09 14:17:46 lp-sasha kernel:  nouveau_drm_device_init+0x1c0/0x880 [nouveau]
Oct 09 14:17:46 lp-sasha kernel:  nouveau_drm_probe+0x11a/0x1e0 [nouveau]
Oct 09 14:17:46 lp-sasha kernel:  pci_device_probe+0xcd/0x140
Oct 09 14:17:46 lp-sasha kernel:  really_probe+0xd8/0x400
Oct 09 14:17:46 lp-sasha kernel:  driver_probe_device+0x4a/0xa0
Oct 09 14:17:46 lp-sasha kernel:  device_driver_attach+0x9c/0xc0
Oct 09 14:17:46 lp-sasha kernel:  __driver_attach+0x6f/0x100
Oct 09 14:17:46 lp-sasha kernel:  ? device_driver_attach+0xc0/0xc0
Oct 09 14:17:46 lp-sasha kernel:  bus_for_each_dev+0x75/0xc0
Oct 09 14:17:46 lp-sasha kernel:  bus_add_driver+0x106/0x1c0
Oct 09 14:17:46 lp-sasha kernel:  driver_register+0x86/0xe0
Oct 09 14:17:46 lp-sasha kernel:  ? 0xffffffffa044e000
Oct 09 14:17:46 lp-sasha kernel:  do_one_initcall+0x48/0x1e0
Oct 09 14:17:46 lp-sasha kernel:  ? _cond_resched+0x11/0x60
Oct 09 14:17:46 lp-sasha kernel:  ? kmem_cache_alloc_trace+0x19c/0x1e0
Oct 09 14:17:46 lp-sasha kernel:  do_init_module+0x57/0x220
Oct 09 14:17:46 lp-sasha kernel:  __do_sys_finit_module+0xa0/0xe0
Oct 09 14:17:46 lp-sasha kernel:  do_syscall_64+0x33/0x40
Oct 09 14:17:46 lp-sasha kernel:  entry_SYSCALL_64_after_hwframe+0x44/0xa9
Oct 09 14:17:46 lp-sasha kernel: RIP: 0033:0x7fd01a060d5d
Oct 09 14:17:46 lp-sasha kernel: Code: 00 c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d e3 70 0c 00 f7 d8 64 89 01 48
Oct 09 14:17:46 lp-sasha kernel: RSP: 002b:00007ffc8ad38a98 EFLAGS: 00000246 ORIG_RAX: 0000000000000139
Oct 09 14:17:46 lp-sasha kernel: RAX: ffffffffffffffda RBX: 0000563f6e7fd530 RCX: 00007fd01a060d5d
Oct 09 14:17:46 lp-sasha kernel: RDX: 0000000000000000 RSI: 00007fd01a19f95d RDI: 000000000000000f
Oct 09 14:17:46 lp-sasha kernel: RBP: 0000000000020000 R08: 0000000000000000 R09: 0000000000000007
Oct 09 14:17:46 lp-sasha kernel: R10: 000000000000000f R11: 0000000000000246 R12: 00007fd01a19f95d
Oct 09 14:17:46 lp-sasha kernel: R13: 0000000000000000 R14: 0000563f6e7fbc10 R15: 0000563f6e7fd530
Oct 09 14:17:46 lp-sasha kernel: Modules linked in: nouveau(+) ttm xt_string xt_mark xt_LOG vgem v4l2_dv_timings uvcvideo ulpi udf ts_kmp ts_fsm ts_bm snd_aloop sil164 qat_dh895xccvf nf_nat_sip nf_nat_irc nf_nat_ftp nf_nat nf_log_ipv6 nf_log_ipv4 nf_log_common ltc2990 lcd intel_qat input_leds i2c_mux gspca_main videobuf2_vmalloc videobuf2_memops videobuf2_v4l2 videobuf2_common videodev mc drivetemp cuse fuse crc_itu_t coretemp ch7006 ath5k ath algif_hash
Oct 09 14:17:46 lp-sasha kernel: CR2: 0000000000000000
Oct 09 14:17:46 lp-sasha kernel: ---[ end trace 0ddafe218ad30017 ]---
Oct 09 14:17:46 lp-sasha kernel: RIP: 0010:nouveau_connector_detect_depth+0x71/0xc0 [nouveau]
Oct 09 14:17:46 lp-sasha kernel: Code: 0a 00 00 48 8b 49 48 c7 87 b8 00 00 00 06 00 00 00 80 b9 4d 0a 00 00 00 75 1e 83 fa 41 75 05 48 85 c0 75 29 8b 81 10 0d 00 00 <39> 06 7c 25 f6 81 14 0d 00 00 02 75 b7 c3 80 b9 0c 0d 00 00 00 75
Oct 09 14:17:46 lp-sasha kernel: RSP: 0018:ffffc9000028f8c0 EFLAGS: 00010297
Oct 09 14:17:46 lp-sasha kernel: RAX: 0000000000014c08 RBX: ffff8880369d4000 RCX: ffff8880369d3000
Oct 09 14:17:46 lp-sasha kernel: RDX: 0000000000000040 RSI: 0000000000000000 RDI: ffff8880369d4000
Oct 09 14:17:46 lp-sasha kernel: RBP: ffff88800601cc00 R08: ffff8880051da298 R09: ffffffff8226201a
Oct 09 14:17:46 lp-sasha kernel: R10: ffff88800469aa80 R11: ffff888004c84ff8 R12: 0000000000000000
Oct 09 14:17:46 lp-sasha kernel: R13: ffff8880051da000 R14: 0000000000002000 R15: 0000000000000003
Oct 09 14:17:46 lp-sasha kernel: FS:  00007fd0192b3440(0000) GS:ffff8880bc900000(0000) knlGS:0000000000000000
Oct 09 14:17:46 lp-sasha kernel: CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
Oct 09 14:17:46 lp-sasha kernel: CR2: 0000000000000000 CR3: 0000000004976000 CR4: 00000000000006e0

The disassembly:
Code: 0a 00 00 48 8b 49 48 c7 87 b8 00 00 00 06 00 00 00 80 b9 4d 0a 00 00 00 75 1e 83 fa 41 75 05 48 85 c0 75 29 8b 81 10 0d 00 00 <39> 06 7c 25 f6 81 14 0d 00 00 02 75 b7 c3 80 b9 0c 0d 00 00 00 75
All code
========
   0:   0a 00                   or     (%rax),%al
   2:   00 48 8b                add    %cl,-0x75(%rax)
   5:   49                      rex.WB
   6:   48 c7 87 b8 00 00 00    movq   $0x6,0xb8(%rdi)
   d:   06 00 00 00
  11:   80 b9 4d 0a 00 00 00    cmpb   $0x0,0xa4d(%rcx)
  18:   75 1e                   jne    0x38
  1a:   83 fa 41                cmp    $0x41,%edx
  1d:   75 05                   jne    0x24
  1f:   48 85 c0                test   %rax,%rax
  22:   75 29                   jne    0x4d
  24:   8b 81 10 0d 00 00       mov    0xd10(%rcx),%eax
  2a:*  39 06                   cmp    %eax,(%rsi)              <-- trapping instruction
  2c:   7c 25                   jl     0x53
  2e:   f6 81 14 0d 00 00 02    testb  $0x2,0xd14(%rcx)
  35:   75 b7                   jne    0xffffffffffffffee
  37:   c3                      retq
  38:   80 b9 0c 0d 00 00 00    cmpb   $0x0,0xd0c(%rcx)
  3f:   75                      .byte 0x75

Code starting with the faulting instruction
===========================================
   0:   39 06                   cmp    %eax,(%rsi)
   2:   7c 25                   jl     0x29
   4:   f6 81 14 0d 00 00 02    testb  $0x2,0xd14(%rcx)
   b:   75 b7                   jne    0xffffffffffffffc4
   d:   c3                      retq
   e:   80 b9 0c 0d 00 00 00    cmpb   $0x0,0xd0c(%rcx)
  15:   75                      .byte 0x75

objdump -SF --disassemble=nouveau_connector_detect_depth
[...]
        if (nv_connector->edid &&
   c85e1:       83 fa 41                cmp    $0x41,%edx
   c85e4:       75 05                   jne    c85eb <nouveau_connector_detect_depth+0x6b> (File Offset: 0xc866b)
   c85e6:       48 85 c0                test   %rax,%rax
   c85e9:       75 29                   jne    c8614 <nouveau_connector_detect_depth+0x94> (File Offset: 0xc8694)
            nv_connector->type == DCB_CONNECTOR_LVDS_SPWG)
                duallink = ((u8 *)nv_connector->edid)[121] == 2;
        else
                duallink = mode->clock >= bios->fp.duallink_transition_clk;

        if ((!duallink && (bios->fp.strapless_is_24bit & 1)) ||
   c85eb:       8b 81 10 0d 00 00       mov    0xd10(%rcx),%eax
   c85f1:       39 06                   cmp    %eax,(%rsi)
   c85f3:       7c 25                   jl     c861a <nouveau_connector_detect_depth+0x9a> (File Offset: 0xc869a)
            ( duallink && (bios->fp.strapless_is_24bit & 2)))
   c85f5:       f6 81 14 0d 00 00 02    testb  $0x2,0xd14(%rcx)
   c85fc:       75 b7                   jne    c85b5 <nouveau_connector_detect_depth+0x35> (File Offset: 0xc8635)
                connector->display_info.bpc = 8;
[...]

% scripts/faddr2line /lib/modules/5.9.0-rc8-next-20201009/kernel/drivers/gpu/drm/nouveau/nouveau.ko nouveau_connector_detect_depth+0x71/0xc0
nouveau_connector_detect_depth+0x71/0xc0:
nouveau_connector_detect_depth at /home/sasha/linux-next/drivers/gpu/drm/nouveau/nouveau_connector.c:891

It is actually line 889. See the disassembly below.
889                     duallink = mode->clock >= bios->fp.duallink_transition_clk;

The NULL pointer being dereferenced is mode.

Git bisect has identified the following commit as bad:
f28e32d drm/nouveau/kms: Don't change EDID when it hasn't actually changed

Here is the chain of events that causes the oops.
On entry to nouveau_connector_detect_lvds, edid is set to NULL.  The call
to nouveau_connector_detect sets nv_connector->edid to valid memory,
with status set to connector_status_connected and the flow of execution
branching to the out label.

The subsequent call to nouveau_connector_set_edid erronously clears
nv_connector->edid, via the local edid pointer which remains set to NULL.

Fix this by setting edid to the value of the just acquired
nv_connector->edid and executing the body of nouveau_connector_set_edid
only if nv_connector->edid and edid point to different memory addresses
thus preventing nv_connector->edid from being turned into a dangling
pointer.

Fixes: f28e32d ("drm/nouveau/kms: Don't change EDID when it hasn't actually changed")
Signed-off-by: Alexander Kapshuk <alexander.kapshuk@gmail.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
frank-w pushed a commit that referenced this issue Aug 31, 2023
…tect_depth

commit 630f512 upstream.

This oops manifests itself on the following hardware:
01:00.0 VGA compatible controller: NVIDIA Corporation G98M [GeForce G 103M] (rev a1)

Oct 09 14:17:46 lp-sasha kernel: BUG: kernel NULL pointer dereference, address: 0000000000000000
Oct 09 14:17:46 lp-sasha kernel: #PF: supervisor read access in kernel mode
Oct 09 14:17:46 lp-sasha kernel: #PF: error_code(0x0000) - not-present page
Oct 09 14:17:46 lp-sasha kernel: PGD 0 P4D 0
Oct 09 14:17:46 lp-sasha kernel: Oops: 0000 [#1] SMP PTI
Oct 09 14:17:46 lp-sasha kernel: CPU: 1 PID: 191 Comm: systemd-udevd Not tainted 5.9.0-rc8-next-20201009 #38
Oct 09 14:17:46 lp-sasha kernel: Hardware name: Hewlett-Packard Compaq Presario CQ61 Notebook PC/306A, BIOS F.03 03/23/2009
Oct 09 14:17:46 lp-sasha kernel: RIP: 0010:nouveau_connector_detect_depth+0x71/0xc0 [nouveau]
Oct 09 14:17:46 lp-sasha kernel: Code: 0a 00 00 48 8b 49 48 c7 87 b8 00 00 00 06 00 00 00 80 b9 4d 0a 00 00 00 75 1e 83 fa 41 75 05 48 85 c0 75 29 8b 81 10 0d 00 00 <39> 06 7c 25 f6 81 14 0d 00 00 02 75 b7 c3 80 b9 0c 0d 00 00 00 75
Oct 09 14:17:46 lp-sasha kernel: RSP: 0018:ffffc9000028f8c0 EFLAGS: 00010297
Oct 09 14:17:46 lp-sasha kernel: RAX: 0000000000014c08 RBX: ffff8880369d4000 RCX: ffff8880369d3000
Oct 09 14:17:46 lp-sasha kernel: RDX: 0000000000000040 RSI: 0000000000000000 RDI: ffff8880369d4000
Oct 09 14:17:46 lp-sasha kernel: RBP: ffff88800601cc00 R08: ffff8880051da298 R09: ffffffff8226201a
Oct 09 14:17:46 lp-sasha kernel: R10: ffff88800469aa80 R11: ffff888004c84ff8 R12: 0000000000000000
Oct 09 14:17:46 lp-sasha kernel: R13: ffff8880051da000 R14: 0000000000002000 R15: 0000000000000003
Oct 09 14:17:46 lp-sasha kernel: FS:  00007fd0192b3440(0000) GS:ffff8880bc900000(0000) knlGS:0000000000000000
Oct 09 14:17:46 lp-sasha kernel: CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
Oct 09 14:17:46 lp-sasha kernel: CR2: 0000000000000000 CR3: 0000000004976000 CR4: 00000000000006e0
Oct 09 14:17:46 lp-sasha kernel: Call Trace:
Oct 09 14:17:46 lp-sasha kernel:  nouveau_connector_get_modes+0x1e6/0x240 [nouveau]
Oct 09 14:17:46 lp-sasha kernel:  ? kfree+0xb9/0x240
Oct 09 14:17:46 lp-sasha kernel:  ? drm_connector_list_iter_next+0x7c/0xa0
Oct 09 14:17:46 lp-sasha kernel:  drm_helper_probe_single_connector_modes+0x1ba/0x7c0
Oct 09 14:17:46 lp-sasha kernel:  drm_client_modeset_probe+0x27e/0x1360
Oct 09 14:17:46 lp-sasha kernel:  ? nvif_object_sclass_put+0xc/0x20 [nouveau]
Oct 09 14:17:46 lp-sasha kernel:  ? nouveau_cli_init+0x3cc/0x440 [nouveau]
Oct 09 14:17:46 lp-sasha kernel:  ? ktime_get_mono_fast_ns+0x49/0xa0
Oct 09 14:17:46 lp-sasha kernel:  ? nouveau_drm_open+0x4e/0x180 [nouveau]
Oct 09 14:17:46 lp-sasha kernel:  __drm_fb_helper_initial_config_and_unlock+0x3f/0x4a0
Oct 09 14:17:46 lp-sasha kernel:  ? drm_file_alloc+0x18f/0x260
Oct 09 14:17:46 lp-sasha kernel:  ? mutex_lock+0x9/0x40
Oct 09 14:17:46 lp-sasha kernel:  ? drm_client_init+0x110/0x160
Oct 09 14:17:46 lp-sasha kernel:  nouveau_fbcon_init+0x14d/0x1c0 [nouveau]
Oct 09 14:17:46 lp-sasha kernel:  nouveau_drm_device_init+0x1c0/0x880 [nouveau]
Oct 09 14:17:46 lp-sasha kernel:  nouveau_drm_probe+0x11a/0x1e0 [nouveau]
Oct 09 14:17:46 lp-sasha kernel:  pci_device_probe+0xcd/0x140
Oct 09 14:17:46 lp-sasha kernel:  really_probe+0xd8/0x400
Oct 09 14:17:46 lp-sasha kernel:  driver_probe_device+0x4a/0xa0
Oct 09 14:17:46 lp-sasha kernel:  device_driver_attach+0x9c/0xc0
Oct 09 14:17:46 lp-sasha kernel:  __driver_attach+0x6f/0x100
Oct 09 14:17:46 lp-sasha kernel:  ? device_driver_attach+0xc0/0xc0
Oct 09 14:17:46 lp-sasha kernel:  bus_for_each_dev+0x75/0xc0
Oct 09 14:17:46 lp-sasha kernel:  bus_add_driver+0x106/0x1c0
Oct 09 14:17:46 lp-sasha kernel:  driver_register+0x86/0xe0
Oct 09 14:17:46 lp-sasha kernel:  ? 0xffffffffa044e000
Oct 09 14:17:46 lp-sasha kernel:  do_one_initcall+0x48/0x1e0
Oct 09 14:17:46 lp-sasha kernel:  ? _cond_resched+0x11/0x60
Oct 09 14:17:46 lp-sasha kernel:  ? kmem_cache_alloc_trace+0x19c/0x1e0
Oct 09 14:17:46 lp-sasha kernel:  do_init_module+0x57/0x220
Oct 09 14:17:46 lp-sasha kernel:  __do_sys_finit_module+0xa0/0xe0
Oct 09 14:17:46 lp-sasha kernel:  do_syscall_64+0x33/0x40
Oct 09 14:17:46 lp-sasha kernel:  entry_SYSCALL_64_after_hwframe+0x44/0xa9
Oct 09 14:17:46 lp-sasha kernel: RIP: 0033:0x7fd01a060d5d
Oct 09 14:17:46 lp-sasha kernel: Code: 00 c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d e3 70 0c 00 f7 d8 64 89 01 48
Oct 09 14:17:46 lp-sasha kernel: RSP: 002b:00007ffc8ad38a98 EFLAGS: 00000246 ORIG_RAX: 0000000000000139
Oct 09 14:17:46 lp-sasha kernel: RAX: ffffffffffffffda RBX: 0000563f6e7fd530 RCX: 00007fd01a060d5d
Oct 09 14:17:46 lp-sasha kernel: RDX: 0000000000000000 RSI: 00007fd01a19f95d RDI: 000000000000000f
Oct 09 14:17:46 lp-sasha kernel: RBP: 0000000000020000 R08: 0000000000000000 R09: 0000000000000007
Oct 09 14:17:46 lp-sasha kernel: R10: 000000000000000f R11: 0000000000000246 R12: 00007fd01a19f95d
Oct 09 14:17:46 lp-sasha kernel: R13: 0000000000000000 R14: 0000563f6e7fbc10 R15: 0000563f6e7fd530
Oct 09 14:17:46 lp-sasha kernel: Modules linked in: nouveau(+) ttm xt_string xt_mark xt_LOG vgem v4l2_dv_timings uvcvideo ulpi udf ts_kmp ts_fsm ts_bm snd_aloop sil164 qat_dh895xccvf nf_nat_sip nf_nat_irc nf_nat_ftp nf_nat nf_log_ipv6 nf_log_ipv4 nf_log_common ltc2990 lcd intel_qat input_leds i2c_mux gspca_main videobuf2_vmalloc videobuf2_memops videobuf2_v4l2 videobuf2_common videodev mc drivetemp cuse fuse crc_itu_t coretemp ch7006 ath5k ath algif_hash
Oct 09 14:17:46 lp-sasha kernel: CR2: 0000000000000000
Oct 09 14:17:46 lp-sasha kernel: ---[ end trace 0ddafe218ad30017 ]---
Oct 09 14:17:46 lp-sasha kernel: RIP: 0010:nouveau_connector_detect_depth+0x71/0xc0 [nouveau]
Oct 09 14:17:46 lp-sasha kernel: Code: 0a 00 00 48 8b 49 48 c7 87 b8 00 00 00 06 00 00 00 80 b9 4d 0a 00 00 00 75 1e 83 fa 41 75 05 48 85 c0 75 29 8b 81 10 0d 00 00 <39> 06 7c 25 f6 81 14 0d 00 00 02 75 b7 c3 80 b9 0c 0d 00 00 00 75
Oct 09 14:17:46 lp-sasha kernel: RSP: 0018:ffffc9000028f8c0 EFLAGS: 00010297
Oct 09 14:17:46 lp-sasha kernel: RAX: 0000000000014c08 RBX: ffff8880369d4000 RCX: ffff8880369d3000
Oct 09 14:17:46 lp-sasha kernel: RDX: 0000000000000040 RSI: 0000000000000000 RDI: ffff8880369d4000
Oct 09 14:17:46 lp-sasha kernel: RBP: ffff88800601cc00 R08: ffff8880051da298 R09: ffffffff8226201a
Oct 09 14:17:46 lp-sasha kernel: R10: ffff88800469aa80 R11: ffff888004c84ff8 R12: 0000000000000000
Oct 09 14:17:46 lp-sasha kernel: R13: ffff8880051da000 R14: 0000000000002000 R15: 0000000000000003
Oct 09 14:17:46 lp-sasha kernel: FS:  00007fd0192b3440(0000) GS:ffff8880bc900000(0000) knlGS:0000000000000000
Oct 09 14:17:46 lp-sasha kernel: CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
Oct 09 14:17:46 lp-sasha kernel: CR2: 0000000000000000 CR3: 0000000004976000 CR4: 00000000000006e0

The disassembly:
Code: 0a 00 00 48 8b 49 48 c7 87 b8 00 00 00 06 00 00 00 80 b9 4d 0a 00 00 00 75 1e 83 fa 41 75 05 48 85 c0 75 29 8b 81 10 0d 00 00 <39> 06 7c 25 f6 81 14 0d 00 00 02 75 b7 c3 80 b9 0c 0d 00 00 00 75
All code
========
   0:   0a 00                   or     (%rax),%al
   2:   00 48 8b                add    %cl,-0x75(%rax)
   5:   49                      rex.WB
   6:   48 c7 87 b8 00 00 00    movq   $0x6,0xb8(%rdi)
   d:   06 00 00 00
  11:   80 b9 4d 0a 00 00 00    cmpb   $0x0,0xa4d(%rcx)
  18:   75 1e                   jne    0x38
  1a:   83 fa 41                cmp    $0x41,%edx
  1d:   75 05                   jne    0x24
  1f:   48 85 c0                test   %rax,%rax
  22:   75 29                   jne    0x4d
  24:   8b 81 10 0d 00 00       mov    0xd10(%rcx),%eax
  2a:*  39 06                   cmp    %eax,(%rsi)              <-- trapping instruction
  2c:   7c 25                   jl     0x53
  2e:   f6 81 14 0d 00 00 02    testb  $0x2,0xd14(%rcx)
  35:   75 b7                   jne    0xffffffffffffffee
  37:   c3                      retq
  38:   80 b9 0c 0d 00 00 00    cmpb   $0x0,0xd0c(%rcx)
  3f:   75                      .byte 0x75

Code starting with the faulting instruction
===========================================
   0:   39 06                   cmp    %eax,(%rsi)
   2:   7c 25                   jl     0x29
   4:   f6 81 14 0d 00 00 02    testb  $0x2,0xd14(%rcx)
   b:   75 b7                   jne    0xffffffffffffffc4
   d:   c3                      retq
   e:   80 b9 0c 0d 00 00 00    cmpb   $0x0,0xd0c(%rcx)
  15:   75                      .byte 0x75

objdump -SF --disassemble=nouveau_connector_detect_depth
[...]
        if (nv_connector->edid &&
   c85e1:       83 fa 41                cmp    $0x41,%edx
   c85e4:       75 05                   jne    c85eb <nouveau_connector_detect_depth+0x6b> (File Offset: 0xc866b)
   c85e6:       48 85 c0                test   %rax,%rax
   c85e9:       75 29                   jne    c8614 <nouveau_connector_detect_depth+0x94> (File Offset: 0xc8694)
            nv_connector->type == DCB_CONNECTOR_LVDS_SPWG)
                duallink = ((u8 *)nv_connector->edid)[121] == 2;
        else
                duallink = mode->clock >= bios->fp.duallink_transition_clk;

        if ((!duallink && (bios->fp.strapless_is_24bit & 1)) ||
   c85eb:       8b 81 10 0d 00 00       mov    0xd10(%rcx),%eax
   c85f1:       39 06                   cmp    %eax,(%rsi)
   c85f3:       7c 25                   jl     c861a <nouveau_connector_detect_depth+0x9a> (File Offset: 0xc869a)
            ( duallink && (bios->fp.strapless_is_24bit & 2)))
   c85f5:       f6 81 14 0d 00 00 02    testb  $0x2,0xd14(%rcx)
   c85fc:       75 b7                   jne    c85b5 <nouveau_connector_detect_depth+0x35> (File Offset: 0xc8635)
                connector->display_info.bpc = 8;
[...]

% scripts/faddr2line /lib/modules/5.9.0-rc8-next-20201009/kernel/drivers/gpu/drm/nouveau/nouveau.ko nouveau_connector_detect_depth+0x71/0xc0
nouveau_connector_detect_depth+0x71/0xc0:
nouveau_connector_detect_depth at /home/sasha/linux-next/drivers/gpu/drm/nouveau/nouveau_connector.c:891

It is actually line 889. See the disassembly below.
889                     duallink = mode->clock >= bios->fp.duallink_transition_clk;

The NULL pointer being dereferenced is mode.

Git bisect has identified the following commit as bad:
f28e32d drm/nouveau/kms: Don't change EDID when it hasn't actually changed

Here is the chain of events that causes the oops.
On entry to nouveau_connector_detect_lvds, edid is set to NULL.  The call
to nouveau_connector_detect sets nv_connector->edid to valid memory,
with status set to connector_status_connected and the flow of execution
branching to the out label.

The subsequent call to nouveau_connector_set_edid erronously clears
nv_connector->edid, via the local edid pointer which remains set to NULL.

Fix this by setting edid to the value of the just acquired
nv_connector->edid and executing the body of nouveau_connector_set_edid
only if nv_connector->edid and edid point to different memory addresses
thus preventing nv_connector->edid from being turned into a dangling
pointer.

Fixes: f28e32d ("drm/nouveau/kms: Don't change EDID when it hasn't actually changed")
Signed-off-by: Alexander Kapshuk <alexander.kapshuk@gmail.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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