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kernel build not 32 bit clean #22

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mcmechan opened this issue Apr 12, 2015 · 1 comment
Closed

kernel build not 32 bit clean #22

mcmechan opened this issue Apr 12, 2015 · 1 comment

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@mcmechan
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The kernel compile uses 64 bit addresses when building on a 32 bit host either on the ci20 itself or on a x86 32 bit host. When built on a 64 bit host it throws away the high 32 bits of the load address, but on both mips and x86 it will stop processing in the mkimage strtoul at one 32 bit word's worth of data which is that annoying freeze or crash where it trys to uncompress to address 0xffffffff

Booting kernel from Legacy Image at 88000000 ...
Image Name: Linux-3.18.3+
Image Type: MIPS Linux Kernel Image (gzip compressed)
Data Size: 3816747 Bytes = 3.6 MiB
Load Address: ffffffff <=== Problem
Entry Point: 805bdc10
Verifying Checksum ... OK
Uncompressing Kernel Image ...

and I have not found a way to set it in u-boot. Also you can't change the 0xffffffff80001000 in arch/mips/jz47[48]0/Platform because it is being used as some sort of magic flag and without the 0xffffffff part it doesn't know how to build a uImage. Currently I have patched mkimage to see if that fixes it, it took 1 hour to compile with make -j3 on the ci20.

Alas markdown does not seem to have a way to turn itself off so I can't include the two line patch so here is a sed script to do it instead.

sed -i "s/strtoul /strtoull /" tools/mkimage.c

The kernel really should be fixed to be 32 bit clean, magiclly dropping the high bits of the load address seems way out there.

@wcohen
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wcohen commented Feb 22, 2016

A patch submitted to u-boot mailing list (https://patchwork.ozlabs.org/patch/583426/) has enabled self-hosted build of the linux-3.18.3 kernel checked out from https://github.com/MIPS/CI20_linux.git .

trini pushed a commit to trini/u-boot that referenced this issue Feb 24, 2016
To follow the MIPS 32-bit and 64-bit memory map conventions (*) recent
MIPS Linux kernels are using a 64-bit sign extended value
(0xffffffff80010000) for the 32-bit load address (0x80010000) of the
Creator CI20 board kernel.  When this 64-bit argument was passed to
mkimage running on a 32-bit machine such as the Creator CI20 board the
load address was incorrectly formed from the upper 32-bit sign-extend
bits (0xffffffff) by the strtoul instead of from the lower 32-bits
(0x80010000).  The mkimage should be able to tolerate the longer
sign-extended 64-bit version of the 32-bit arguments with the use of
strtoull.  Use of the strtoll in place of the strtol in mkimage.c
resolves the issue of self hosted kernel builds for the Creator CI20
board (+) and (++).

(*) http://techpubs.sgi.com/library/dynaweb_docs/0620/SGI_Developer/books/DevDriver_PG/sgi_html/ch01.html
(+) MIPS/CI20_linux#23
(++) MIPS/CI20_linux#22

Signed-off-by: William Cohen <wcohen@redhat.com>
trini pushed a commit to trini/u-boot that referenced this issue Feb 24, 2016
To follow the MIPS 32-bit and 64-bit memory map conventions (*) recent
MIPS Linux kernels are using a 64-bit sign extended value
(0xffffffff80010000) for the 32-bit load address (0x80010000) of the
Creator CI20 board kernel.  When this 64-bit argument was passed to
mkimage running on a 32-bit machine such as the Creator CI20 board the
load address was incorrectly formed from the upper 32-bit sign-extend
bits (0xffffffff) by the strtoul instead of from the lower 32-bits
(0x80010000).  The mkimage should be able to tolerate the longer
sign-extended 64-bit version of the 32-bit arguments with the use of
strtoull.  Use of the strtoll in place of the strtol in mkimage.c
resolves the issue of self hosted kernel builds for the Creator CI20
board (+) and (++).

(*) http://techpubs.sgi.com/library/dynaweb_docs/0620/SGI_Developer/books/DevDriver_PG/sgi_html/ch01.html
(+) MIPS/CI20_linux#23
(++) MIPS/CI20_linux#22

Signed-off-by: William Cohen <wcohen@redhat.com>
trini pushed a commit to trini/u-boot that referenced this issue Feb 24, 2016
To follow the MIPS 32-bit and 64-bit memory map conventions (*) recent
MIPS Linux kernels are using a 64-bit sign extended value
(0xffffffff80010000) for the 32-bit load address (0x80010000) of the
Creator CI20 board kernel.  When this 64-bit argument was passed to
mkimage running on a 32-bit machine such as the Creator CI20 board the
load address was incorrectly formed from the upper 32-bit sign-extend
bits (0xffffffff) by the strtoul instead of from the lower 32-bits
(0x80010000).  The mkimage should be able to tolerate the longer
sign-extended 64-bit version of the 32-bit arguments with the use of
strtoull.  Use of the strtoll in place of the strtol in mkimage.c
resolves the issue of self hosted kernel builds for the Creator CI20
board (+) and (++).

(*) http://techpubs.sgi.com/library/dynaweb_docs/0620/SGI_Developer/books/DevDriver_PG/sgi_html/ch01.html
(+) MIPS/CI20_linux#23
(++) MIPS/CI20_linux#22

Signed-off-by: William Cohen <wcohen@redhat.com>
trini pushed a commit to trini/u-boot that referenced this issue Feb 24, 2016
To follow the MIPS 32-bit and 64-bit memory map conventions (*) recent
MIPS Linux kernels are using a 64-bit sign extended value
(0xffffffff80010000) for the 32-bit load address (0x80010000) of the
Creator CI20 board kernel.  When this 64-bit argument was passed to
mkimage running on a 32-bit machine such as the Creator CI20 board the
load address was incorrectly formed from the upper 32-bit sign-extend
bits (0xffffffff) by the strtoul instead of from the lower 32-bits
(0x80010000).  The mkimage should be able to tolerate the longer
sign-extended 64-bit version of the 32-bit arguments with the use of
strtoull.  Use of the strtoll in place of the strtol in mkimage.c
resolves the issue of self hosted kernel builds for the Creator CI20
board (+) and (++).

(*) http://techpubs.sgi.com/library/dynaweb_docs/0620/SGI_Developer/books/DevDriver_PG/sgi_html/ch01.html
(+) MIPS/CI20_linux#23
(++) MIPS/CI20_linux#22

Signed-off-by: William Cohen <wcohen@redhat.com>
pcercuei pushed a commit to OpenDingux/linux that referenced this issue May 16, 2018
syzbot caught an infinite recursion in nsh_gso_segment().

Problem here is that we need to make sure the NSH header is of
reasonable length.

BUG: MAX_LOCK_DEPTH too low!
turning off the locking correctness validator.
depth: 48  max: 48!
48 locks held by syz-executor0/10189:
 #0:         (ptrval) (rcu_read_lock_bh){....}, at: __dev_queue_xmit+0x30f/0x34c0 net/core/dev.c:3517
 #1:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #1:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #2:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #2:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #3:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #3:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #4:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #4:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #5:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #5:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #6:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #6:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #7:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #7:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #8:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #8:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #9:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #9:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #10:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #10:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #11:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #11:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #12:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #12:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #13:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #13:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #14:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #14:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #15:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #15:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 MIPS#16:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 MIPS#16:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 MIPS#17:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 MIPS#17:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 MIPS#18:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 MIPS#18:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 MIPS#19:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 MIPS#19:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 MIPS#20:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 MIPS#20:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 MIPS#21:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 MIPS#21:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 MIPS#22:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 MIPS#22:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 MIPS#23:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 MIPS#23:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 MIPS#24:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 MIPS#24:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 MIPS#25:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 MIPS#25:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 MIPS#26:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 MIPS#26:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 MIPS#27:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 MIPS#27:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 MIPS#28:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 MIPS#28:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 MIPS#29:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 MIPS#29:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 MIPS#30:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 MIPS#30:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 MIPS#31:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 MIPS#31:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
dccp_close: ABORT with 65423 bytes unread
 MIPS#32:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 MIPS#32:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 MIPS#33:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 MIPS#33:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 MIPS#34:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 MIPS#34:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 MIPS#35:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 MIPS#35:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 MIPS#36:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 MIPS#36:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 MIPS#37:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 MIPS#37:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 MIPS#38:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 MIPS#38:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 MIPS#39:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 MIPS#39:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 MIPS#40:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 MIPS#40:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 MIPS#41:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 MIPS#41:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 MIPS#42:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 MIPS#42:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 MIPS#43:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 MIPS#43:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 MIPS#44:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 MIPS#44:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 MIPS#45:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 MIPS#45:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 MIPS#46:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 MIPS#46:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 MIPS#47:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 MIPS#47:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
INFO: lockdep is turned off.
CPU: 1 PID: 10189 Comm: syz-executor0 Not tainted 4.17.0-rc2+ MIPS#26
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1b9/0x294 lib/dump_stack.c:113
 __lock_acquire+0x1788/0x5140 kernel/locking/lockdep.c:3449
 lock_acquire+0x1dc/0x520 kernel/locking/lockdep.c:3920
 rcu_lock_acquire include/linux/rcupdate.h:246 [inline]
 rcu_read_lock include/linux/rcupdate.h:632 [inline]
 skb_mac_gso_segment+0x25b/0x720 net/core/dev.c:2789
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 __skb_gso_segment+0x3bb/0x870 net/core/dev.c:2865
 skb_gso_segment include/linux/netdevice.h:4025 [inline]
 validate_xmit_skb+0x54d/0xd90 net/core/dev.c:3118
 validate_xmit_skb_list+0xbf/0x120 net/core/dev.c:3168
 sch_direct_xmit+0x354/0x11e0 net/sched/sch_generic.c:312
 qdisc_restart net/sched/sch_generic.c:399 [inline]
 __qdisc_run+0x741/0x1af0 net/sched/sch_generic.c:410
 __dev_xmit_skb net/core/dev.c:3243 [inline]
 __dev_queue_xmit+0x28ea/0x34c0 net/core/dev.c:3551
 dev_queue_xmit+0x17/0x20 net/core/dev.c:3616
 packet_snd net/packet/af_packet.c:2951 [inline]
 packet_sendmsg+0x40f8/0x6070 net/packet/af_packet.c:2976
 sock_sendmsg_nosec net/socket.c:629 [inline]
 sock_sendmsg+0xd5/0x120 net/socket.c:639
 __sys_sendto+0x3d7/0x670 net/socket.c:1789
 __do_sys_sendto net/socket.c:1801 [inline]
 __se_sys_sendto net/socket.c:1797 [inline]
 __x64_sys_sendto+0xe1/0x1a0 net/socket.c:1797
 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Fixes: c411ed8 ("nsh: add GSO support")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Jiri Benc <jbenc@redhat.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Acked-by: Jiri Benc <jbenc@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
pcercuei pushed a commit to OpenDingux/linux that referenced this issue Jul 3, 2018
Wire up io_pgetevents system call on powerpc.

io_pgetevents is a new syscall to read asynchronous I/O events from the
completion queue.

Tested with libaio branch aio-poll[1] and the io_pgetevents test (MIPS#22) passed
on both ppc64 LE and BE modes.

[1] https://pagure.io/libaio/branch/aio-poll

CC: Christoph Hellwig <hch@lst.de>
Signed-off-by: Breno Leitao <leitao@debian.org>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
pcercuei pushed a commit to OpenDingux/linux that referenced this issue Jul 24, 2018
Crash dump shows following instructions

crash> bt
PID: 0      TASK: ffffffffbe412480  CPU: 0   COMMAND: "swapper/0"
 #0 [ffff891ee0003868] machine_kexec at ffffffffbd063ef1
 #1 [ffff891ee00038c8] __crash_kexec at ffffffffbd12b6f2
 #2 [ffff891ee0003998] crash_kexec at ffffffffbd12c84c
 #3 [ffff891ee00039b8] oops_end at ffffffffbd030f0a
 #4 [ffff891ee00039e0] no_context at ffffffffbd074643
 #5 [ffff891ee0003a40] __bad_area_nosemaphore at ffffffffbd07496e
 #6 [ffff891ee0003a90] bad_area_nosemaphore at ffffffffbd074a64
 #7 [ffff891ee0003aa0] __do_page_fault at ffffffffbd074b0a
 #8 [ffff891ee0003b18] do_page_fault at ffffffffbd074fc8
 #9 [ffff891ee0003b50] page_fault at ffffffffbda01925
    [exception RIP: qlt_schedule_sess_for_deletion+15]
    RIP: ffffffffc02e526f  RSP: ffff891ee0003c08  RFLAGS: 00010046
    RAX: 0000000000000000  RBX: 0000000000000000  RCX: ffffffffc0307847
    RDX: 00000000000020e6  RSI: ffff891edbc377c8  RDI: 0000000000000000
    RBP: ffff891ee0003c18   R8: ffffffffc02f0b20   R9: 0000000000000250
    R10: 0000000000000258  R11: 000000000000b780  R12: ffff891ed9b43000
    R13: 00000000000000f0  R14: 0000000000000006  R15: ffff891edbc377c8
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
 #10 [ffff891ee0003c20] qla2x00_fcport_event_handler at ffffffffc02853d3 [qla2xxx]
 #11 [ffff891ee0003cf0] __dta_qla24xx_async_gnl_sp_done_333 at ffffffffc0285a1d [qla2xxx]
 #12 [ffff891ee0003de8] qla24xx_process_response_queue at ffffffffc02a2eb5 [qla2xxx]
 #13 [ffff891ee0003e88] qla24xx_msix_rsp_q at ffffffffc02a5403 [qla2xxx]
 #14 [ffff891ee0003ec0] __handle_irq_event_percpu at ffffffffbd0f4c59
 #15 [ffff891ee0003f10] handle_irq_event_percpu at ffffffffbd0f4e02
 MIPS#16 [ffff891ee0003f40] handle_irq_event at ffffffffbd0f4e90
 MIPS#17 [ffff891ee0003f68] handle_edge_irq at ffffffffbd0f8984
 MIPS#18 [ffff891ee0003f88] handle_irq at ffffffffbd0305d5
 MIPS#19 [ffff891ee0003fb8] do_IRQ at ffffffffbda02a18
 --- <IRQ stack> ---
 MIPS#20 [ffffffffbe403d30] ret_from_intr at ffffffffbda0094e
    [exception RIP: unknown or invalid address]
    RIP: 000000000000001f  RSP: 0000000000000000  RFLAGS: fff3b8c2091ebb3f
    RAX: ffffbba5a0000200  RBX: 0000be8cdfa8f9fa  RCX: 0000000000000018
    RDX: 0000000000000101  RSI: 000000000000015d  RDI: 0000000000000193
    RBP: 0000000000000083   R8: ffffffffbe403e38   R9: 0000000000000002
    R10: 0000000000000000  R11: ffffffffbe56b820  R12: ffff891ee001cf00
    R13: ffffffffbd11c0a4  R14: ffffffffbe403d60  R15: 0000000000000001
    ORIG_RAX: ffff891ee0022ac0  CS: 0000  SS: ffffffffffffffb9
 bt: WARNING: possibly bogus exception frame
 MIPS#21 [ffffffffbe403dd8] cpuidle_enter_state at ffffffffbd67c6fd
 MIPS#22 [ffffffffbe403e40] cpuidle_enter at ffffffffbd67c907
 MIPS#23 [ffffffffbe403e50] call_cpuidle at ffffffffbd0d98f3
 MIPS#24 [ffffffffbe403e60] do_idle at ffffffffbd0d9b42
 MIPS#25 [ffffffffbe403e98] cpu_startup_entry at ffffffffbd0d9da3
 MIPS#26 [ffffffffbe403ec0] rest_init at ffffffffbd81d4aa
 MIPS#27 [ffffffffbe403ed0] start_kernel at ffffffffbe67d2ca
 MIPS#28 [ffffffffbe403f28] x86_64_start_reservations at ffffffffbe67c675
 MIPS#29 [ffffffffbe403f38] x86_64_start_kernel at ffffffffbe67c6eb
 MIPS#30 [ffffffffbe403f50] secondary_startup_64 at ffffffffbd0000d5

Fixes: 040036b ("scsi: qla2xxx: Delay loop id allocation at login")
Cc: <stable@vger.kernel.org> # v4.17+
Signed-off-by: Chuck Anderson <chuck.anderson@oracle.com>
Signed-off-by: Himanshu Madhani <himanshu.madhani@cavium.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
pcercuei pushed a commit to OpenDingux/linux that referenced this issue May 6, 2019
Move ieee80211_tx_status_ext() outside of status_list lock section
in order to avoid locking dependency and possible deadlock reposed by
LOCKDEP in below warning.

Also do mt76_tx_status_lock() just before it's needed.

[  440.224832] WARNING: possible circular locking dependency detected
[  440.224833] 5.1.0-rc2+ MIPS#22 Not tainted
[  440.224834] ------------------------------------------------------
[  440.224835] kworker/u16:28/2362 is trying to acquire lock:
[  440.224836] 0000000089b8cacf (&(&q->lock)->rlock#2){+.-.}, at: mt76_wake_tx_queue+0x4c/0xb0 [mt76]
[  440.224842]
               but task is already holding lock:
[  440.224842] 000000002cfedc59 (&(&sta->lock)->rlock){+.-.}, at: ieee80211_stop_tx_ba_cb+0x32/0x1f0 [mac80211]
[  440.224863]
               which lock already depends on the new lock.

[  440.224863]
               the existing dependency chain (in reverse order) is:
[  440.224864]
               -> #3 (&(&sta->lock)->rlock){+.-.}:
[  440.224869]        _raw_spin_lock_bh+0x34/0x40
[  440.224880]        ieee80211_start_tx_ba_session+0xe4/0x3d0 [mac80211]
[  440.224894]        minstrel_ht_get_rate+0x45c/0x510 [mac80211]
[  440.224906]        rate_control_get_rate+0xc1/0x140 [mac80211]
[  440.224918]        ieee80211_tx_h_rate_ctrl+0x195/0x3c0 [mac80211]
[  440.224930]        ieee80211_xmit_fast+0x26d/0xa50 [mac80211]
[  440.224942]        __ieee80211_subif_start_xmit+0xfc/0x310 [mac80211]
[  440.224954]        ieee80211_subif_start_xmit+0x38/0x390 [mac80211]
[  440.224956]        dev_hard_start_xmit+0xb8/0x300
[  440.224957]        __dev_queue_xmit+0x7d4/0xbb0
[  440.224968]        ip6_finish_output2+0x246/0x860 [ipv6]
[  440.224978]        mld_sendpack+0x1bd/0x360 [ipv6]
[  440.224987]        mld_ifc_timer_expire+0x1a4/0x2f0 [ipv6]
[  440.224989]        call_timer_fn+0x89/0x2a0
[  440.224990]        run_timer_softirq+0x1bd/0x4d0
[  440.224992]        __do_softirq+0xdb/0x47c
[  440.224994]        irq_exit+0xfa/0x100
[  440.224996]        smp_apic_timer_interrupt+0x9a/0x220
[  440.224997]        apic_timer_interrupt+0xf/0x20
[  440.224999]        cpuidle_enter_state+0xc1/0x470
[  440.225000]        do_idle+0x21a/0x260
[  440.225001]        cpu_startup_entry+0x19/0x20
[  440.225004]        start_secondary+0x135/0x170
[  440.225006]        secondary_startup_64+0xa4/0xb0
[  440.225007]
               -> #2 (&(&sta->rate_ctrl_lock)->rlock){+.-.}:
[  440.225009]        _raw_spin_lock_bh+0x34/0x40
[  440.225022]        rate_control_tx_status+0x4f/0xb0 [mac80211]
[  440.225031]        ieee80211_tx_status_ext+0x142/0x1a0 [mac80211]
[  440.225035]        mt76x02_send_tx_status+0x2e4/0x340 [mt76x02_lib]
[  440.225037]        mt76x02_tx_status_data+0x31/0x40 [mt76x02_lib]
[  440.225040]        mt76u_tx_status_data+0x51/0xa0 [mt76_usb]
[  440.225042]        process_one_work+0x237/0x5d0
[  440.225043]        worker_thread+0x3c/0x390
[  440.225045]        kthread+0x11d/0x140
[  440.225046]        ret_from_fork+0x3a/0x50
[  440.225047]
               -> #1 (&(&list->lock)->rlock#8){+.-.}:
[  440.225049]        _raw_spin_lock_bh+0x34/0x40
[  440.225052]        mt76_tx_status_skb_add+0x51/0x100 [mt76]
[  440.225054]        mt76x02u_tx_prepare_skb+0xbd/0x116 [mt76x02_usb]
[  440.225056]        mt76u_tx_queue_skb+0x5f/0x180 [mt76_usb]
[  440.225058]        mt76_tx+0x93/0x190 [mt76]
[  440.225070]        ieee80211_tx_frags+0x148/0x210 [mac80211]
[  440.225081]        __ieee80211_tx+0x75/0x1b0 [mac80211]
[  440.225092]        ieee80211_tx+0xde/0x110 [mac80211]
[  440.225105]        __ieee80211_tx_skb_tid_band+0x72/0x90 [mac80211]
[  440.225122]        ieee80211_send_auth+0x1f3/0x360 [mac80211]
[  440.225141]        ieee80211_auth.cold.40+0x6c/0x100 [mac80211]
[  440.225156]        ieee80211_mgd_auth.cold.50+0x132/0x15f [mac80211]
[  440.225171]        cfg80211_mlme_auth+0x149/0x360 [cfg80211]
[  440.225181]        nl80211_authenticate+0x273/0x2e0 [cfg80211]
[  440.225183]        genl_family_rcv_msg+0x196/0x3a0
[  440.225184]        genl_rcv_msg+0x47/0x8e
[  440.225185]        netlink_rcv_skb+0x3a/0xf0
[  440.225187]        genl_rcv+0x24/0x40
[  440.225188]        netlink_unicast+0x16d/0x210
[  440.225189]        netlink_sendmsg+0x204/0x3b0
[  440.225191]        sock_sendmsg+0x36/0x40
[  440.225193]        ___sys_sendmsg+0x259/0x2b0
[  440.225194]        __sys_sendmsg+0x47/0x80
[  440.225196]        do_syscall_64+0x60/0x1f0
[  440.225197]        entry_SYSCALL_64_after_hwframe+0x49/0xbe
[  440.225198]
               -> #0 (&(&q->lock)->rlock#2){+.-.}:
[  440.225200]        lock_acquire+0xb9/0x1a0
[  440.225202]        _raw_spin_lock_bh+0x34/0x40
[  440.225204]        mt76_wake_tx_queue+0x4c/0xb0 [mt76]
[  440.225215]        ieee80211_agg_start_txq+0xe8/0x2b0 [mac80211]
[  440.225225]        ieee80211_stop_tx_ba_cb+0xb8/0x1f0 [mac80211]
[  440.225235]        ieee80211_ba_session_work+0x1c1/0x2f0 [mac80211]
[  440.225236]        process_one_work+0x237/0x5d0
[  440.225237]        worker_thread+0x3c/0x390
[  440.225239]        kthread+0x11d/0x140
[  440.225240]        ret_from_fork+0x3a/0x50
[  440.225240]
               other info that might help us debug this:

[  440.225241] Chain exists of:
                 &(&q->lock)->rlock#2 --> &(&sta->rate_ctrl_lock)->rlock --> &(&sta->lock)->rlock

[  440.225243]  Possible unsafe locking scenario:

[  440.225244]        CPU0                    CPU1
[  440.225244]        ----                    ----
[  440.225245]   lock(&(&sta->lock)->rlock);
[  440.225245]                                lock(&(&sta->rate_ctrl_lock)->rlock);
[  440.225246]                                lock(&(&sta->lock)->rlock);
[  440.225247]   lock(&(&q->lock)->rlock#2);
[  440.225248]
                *** DEADLOCK ***

[  440.225249] 5 locks held by kworker/u16:28/2362:
[  440.225250]  #0: 0000000048fcd291 ((wq_completion)phy0){+.+.}, at: process_one_work+0x1b5/0x5d0
[  440.225252]  #1: 00000000f1c6828f ((work_completion)(&sta->ampdu_mlme.work)){+.+.}, at: process_one_work+0x1b5/0x5d0
[  440.225254]  #2: 00000000433d2b2c (&sta->ampdu_mlme.mtx){+.+.}, at: ieee80211_ba_session_work+0x5c/0x2f0 [mac80211]
[  440.225265]  #3: 000000002cfedc59 (&(&sta->lock)->rlock){+.-.}, at: ieee80211_stop_tx_ba_cb+0x32/0x1f0 [mac80211]
[  440.225276]  #4: 000000009d7b9a44 (rcu_read_lock){....}, at: ieee80211_agg_start_txq+0x33/0x2b0 [mac80211]
[  440.225286]
               stack backtrace:
[  440.225288] CPU: 2 PID: 2362 Comm: kworker/u16:28 Not tainted 5.1.0-rc2+ MIPS#22
[  440.225289] Hardware name: LENOVO 20KGS23S0P/20KGS23S0P, BIOS N23ET55W (1.30 ) 08/31/2018
[  440.225300] Workqueue: phy0 ieee80211_ba_session_work [mac80211]
[  440.225301] Call Trace:
[  440.225304]  dump_stack+0x85/0xc0
[  440.225306]  print_circular_bug.isra.38.cold.58+0x15c/0x195
[  440.225307]  check_prev_add.constprop.48+0x5f0/0xc00
[  440.225309]  ? check_prev_add.constprop.48+0x39d/0xc00
[  440.225311]  ? __lock_acquire+0x41d/0x1100
[  440.225312]  __lock_acquire+0xd98/0x1100
[  440.225313]  ? __lock_acquire+0x41d/0x1100
[  440.225315]  lock_acquire+0xb9/0x1a0
[  440.225317]  ? mt76_wake_tx_queue+0x4c/0xb0 [mt76]
[  440.225319]  _raw_spin_lock_bh+0x34/0x40
[  440.225321]  ? mt76_wake_tx_queue+0x4c/0xb0 [mt76]
[  440.225323]  mt76_wake_tx_queue+0x4c/0xb0 [mt76]
[  440.225334]  ieee80211_agg_start_txq+0xe8/0x2b0 [mac80211]
[  440.225344]  ieee80211_stop_tx_ba_cb+0xb8/0x1f0 [mac80211]
[  440.225354]  ieee80211_ba_session_work+0x1c1/0x2f0 [mac80211]
[  440.225356]  process_one_work+0x237/0x5d0
[  440.225358]  worker_thread+0x3c/0x390
[  440.225359]  ? wq_calc_node_cpumask+0x70/0x70
[  440.225360]  kthread+0x11d/0x140
[  440.225362]  ? kthread_create_on_node+0x40/0x40
[  440.225363]  ret_from_fork+0x3a/0x50

Cc: stable@vger.kernel.org
Fixes: 88046b2 ("mt76: add support for reporting tx status with skb")
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Acked-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
pcercuei pushed a commit to OpenDingux/linux that referenced this issue Jan 18, 2020
'chrdev_open()' calls 'cdev_get()' to obtain a reference to the
'struct cdev *' stashed in the 'i_cdev' field of the target inode
structure. If the pointer is NULL, then it is initialised lazily by
looking up the kobject in the 'cdev_map' and so the whole procedure is
protected by the 'cdev_lock' spinlock to serialise initialisation of
the shared pointer.

Unfortunately, it is possible for the initialising thread to fail *after*
installing the new pointer, for example if the subsequent '->open()' call
on the file fails. In this case, 'cdev_put()' is called, the reference
count on the kobject is dropped and, if nobody else has taken a reference,
the release function is called which finally clears 'inode->i_cdev' from
'cdev_purge()' before potentially freeing the object. The problem here
is that a racing thread can happily take the 'cdev_lock' and see the
non-NULL pointer in the inode, which can result in a refcount increment
from zero and a warning:

  |  ------------[ cut here ]------------
  |  refcount_t: addition on 0; use-after-free.
  |  WARNING: CPU: 2 PID: 6385 at lib/refcount.c:25 refcount_warn_saturate+0x6d/0xf0
  |  Modules linked in:
  |  CPU: 2 PID: 6385 Comm: repro Not tainted 5.5.0-rc2+ MIPS#22
  |  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
  |  RIP: 0010:refcount_warn_saturate+0x6d/0xf0
  |  Code: 05 55 9a 15 01 01 e8 9d aa c8 ff 0f 0b c3 80 3d 45 9a 15 01 00 75 ce 48 c7 c7 00 9c 62 b3 c6 08
  |  RSP: 0018:ffffb524c1b9bc70 EFLAGS: 00010282
  |  RAX: 0000000000000000 RBX: ffff9e9da1f71390 RCX: 0000000000000000
  |  RDX: ffff9e9dbbd27618 RSI: ffff9e9dbbd18798 RDI: ffff9e9dbbd18798
  |  RBP: 0000000000000000 R08: 000000000000095f R09: 0000000000000039
  |  R10: 0000000000000000 R11: ffffb524c1b9bb20 R12: ffff9e9da1e8c700
  |  R13: ffffffffb25ee8b0 R14: 0000000000000000 R15: ffff9e9da1e8c700
  |  FS:  00007f3b87d26700(0000) GS:ffff9e9dbbd00000(0000) knlGS:0000000000000000
  |  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  |  CR2: 00007fc16909c000 CR3: 000000012df9c000 CR4: 00000000000006e0
  |  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  |  DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  |  Call Trace:
  |   kobject_get+0x5c/0x60
  |   cdev_get+0x2b/0x60
  |   chrdev_open+0x55/0x220
  |   ? cdev_put.part.3+0x20/0x20
  |   do_dentry_open+0x13a/0x390
  |   path_openat+0x2c8/0x1470
  |   do_filp_open+0x93/0x100
  |   ? selinux_file_ioctl+0x17f/0x220
  |   do_sys_open+0x186/0x220
  |   do_syscall_64+0x48/0x150
  |   entry_SYSCALL_64_after_hwframe+0x44/0xa9
  |  RIP: 0033:0x7f3b87efcd0e
  |  Code: 89 54 24 08 e8 a3 f4 ff ff 8b 74 24 0c 48 8b 3c 24 41 89 c0 44 8b 54 24 08 b8 01 01 00 00 89 f4
  |  RSP: 002b:00007f3b87d259f0 EFLAGS: 00000293 ORIG_RAX: 0000000000000101
  |  RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f3b87efcd0e
  |  RDX: 0000000000000000 RSI: 00007f3b87d25a80 RDI: 00000000ffffff9c
  |  RBP: 00007f3b87d25e90 R08: 0000000000000000 R09: 0000000000000000
  |  R10: 0000000000000000 R11: 0000000000000293 R12: 00007ffe188f504e
  |  R13: 00007ffe188f504f R14: 00007f3b87d26700 R15: 0000000000000000
  |  ---[ end trace 24f53ca58db8180a ]---

Since 'cdev_get()' can already fail to obtain a reference, simply move
it over to use 'kobject_get_unless_zero()' instead of 'kobject_get()',
which will cause the racing thread to return -ENXIO if the initialising
thread fails unexpectedly.

Cc: Hillf Danton <hdanton@sina.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Reported-by: syzbot+82defefbbd8527e1c2cb@syzkaller.appspotmail.com
Signed-off-by: Will Deacon <will@kernel.org>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20191219120203.32691-1-will@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
pcercuei pushed a commit to OpenDingux/linux that referenced this issue Jan 18, 2020
Starting with commit fa212a9 ("iommu/vt-d: Probe DMA-capable ACPI
name space devices"), we now probe DMA-capable ACPI name
space devices. On Dell XPS 13 9343, which has an Intel LPSS platform
device INTL9C60 enumerated via ACPI, this change leads to the following
warning:

    ------------[ cut here ]------------
    WARNING: CPU: 1 PID: 1 at pci_device_group+0x11a/0x130
    CPU: 1 PID: 1 Comm: swapper/0 Tainted: G                T 5.5.0-rc3+ MIPS#22
    Hardware name: Dell Inc. XPS 13 9343/0310JH, BIOS A20 06/06/2019
    RIP: 0010:pci_device_group+0x11a/0x130
    Code: f0 ff ff 48 85 c0 49 89 c4 75 c4 48 8d 74 24 10 48 89 ef e8 48 ef ff ff 48 85 c0 49 89 c4 75 af e8 db f7 ff ff 49 89 c4 eb a5 <0f> 0b 49 c7 c4 ea ff ff ff eb 9a e8 96 1e c7 ff 66 0f 1f 44 00 00
    RSP: 0000:ffffc0d6c0043cb0 EFLAGS: 00010202
    RAX: 0000000000000000 RBX: ffffa3d1d43dd810 RCX: 0000000000000000
    RDX: ffffa3d1d4fecf80 RSI: ffffa3d12943dcc0 RDI: ffffa3d1d43dd810
    RBP: ffffa3d1d43dd810 R08: 0000000000000000 R09: ffffa3d1d4c04a80
    R10: ffffa3d1d4c00880 R11: ffffa3d1d44ba000 R12: 0000000000000000
    R13: ffffa3d1d4383b80 R14: ffffa3d1d4c090d0 R15: ffffa3d1d4324530
    FS:  0000000000000000(0000) GS:ffffa3d1d6700000(0000) knlGS:0000000000000000
    CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
    CR2: 0000000000000000 CR3: 000000000460a001 CR4: 00000000003606e0
    Call Trace:
     ? iommu_group_get_for_dev+0x81/0x1f0
     ? intel_iommu_add_device+0x61/0x170
     ? iommu_probe_device+0x43/0xd0
     ? intel_iommu_init+0x1fa2/0x2235
     ? pci_iommu_init+0x52/0xe7
     ? e820__memblock_setup+0x15c/0x15c
     ? do_one_initcall+0xcc/0x27e
     ? kernel_init_freeable+0x169/0x259
     ? rest_init+0x95/0x95
     ? kernel_init+0x5/0xeb
     ? ret_from_fork+0x35/0x40
    ---[ end trace 28473e7abc25b92c ]---
    DMAR: ACPI name space devices didn't probe correctly

The bug results from the fact that while we now enumerate ACPI devices,
we aren't able to handle any non-PCI device when generating the device
group. Fix the issue by implementing an Intel-specific callback that
returns `pci_device_group` only if the device is a PCI device.
Otherwise, it will return a generic device group.

Fixes: fa212a9 ("iommu/vt-d: Probe DMA-capable ACPI name space devices")
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Cc: stable@vger.kernel.org # v5.3+
Acked-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
pcercuei pushed a commit to OpenDingux/linux that referenced this issue Mar 31, 2020
When experimenting with bpf_send_signal() helper in our production
environment (5.2 based), we experienced a deadlock in NMI mode:
   #5 [ffffc9002219f770] queued_spin_lock_slowpath at ffffffff8110be24
   #6 [ffffc9002219f770] _raw_spin_lock_irqsave at ffffffff81a43012
   #7 [ffffc9002219f780] try_to_wake_up at ffffffff810e7ecd
   #8 [ffffc9002219f7e0] signal_wake_up_state at ffffffff810c7b55
   #9 [ffffc9002219f7f0] __send_signal at ffffffff810c8602
  #10 [ffffc9002219f830] do_send_sig_info at ffffffff810ca31a
  #11 [ffffc9002219f868] bpf_send_signal at ffffffff8119d227
  #12 [ffffc9002219f988] bpf_overflow_handler at ffffffff811d4140
  #13 [ffffc9002219f9e0] __perf_event_overflow at ffffffff811d68cf
  #14 [ffffc9002219fa10] perf_swevent_overflow at ffffffff811d6a09
  #15 [ffffc9002219fa38] ___perf_sw_event at ffffffff811e0f47
  MIPS#16 [ffffc9002219fc30] __schedule at ffffffff81a3e04d
  MIPS#17 [ffffc9002219fc90] schedule at ffffffff81a3e219
  MIPS#18 [ffffc9002219fca0] futex_wait_queue_me at ffffffff8113d1b9
  MIPS#19 [ffffc9002219fcd8] futex_wait at ffffffff8113e529
  MIPS#20 [ffffc9002219fdf0] do_futex at ffffffff8113ffbc
  MIPS#21 [ffffc9002219fec0] __x64_sys_futex at ffffffff81140d1c
  MIPS#22 [ffffc9002219ff38] do_syscall_64 at ffffffff81002602
  MIPS#23 [ffffc9002219ff50] entry_SYSCALL_64_after_hwframe at ffffffff81c00068

The above call stack is actually very similar to an issue
reported by Commit eac9153 ("bpf/stackmap: Fix deadlock with
rq_lock in bpf_get_stack()") by Song Liu. The only difference is
bpf_send_signal() helper instead of bpf_get_stack() helper.

The above deadlock is triggered with a perf_sw_event.
Similar to Commit eac9153, the below almost identical reproducer
used tracepoint point sched/sched_switch so the issue can be easily caught.
  /* stress_test.c */
  #include <stdio.h>
  #include <stdlib.h>
  #include <sys/mman.h>
  #include <pthread.h>
  #include <sys/types.h>
  #include <sys/stat.h>
  #include <fcntl.h>

  #define THREAD_COUNT 1000
  char *filename;
  void *worker(void *p)
  {
        void *ptr;
        int fd;
        char *pptr;

        fd = open(filename, O_RDONLY);
        if (fd < 0)
                return NULL;
        while (1) {
                struct timespec ts = {0, 1000 + rand() % 2000};

                ptr = mmap(NULL, 4096 * 64, PROT_READ, MAP_PRIVATE, fd, 0);
                usleep(1);
                if (ptr == MAP_FAILED) {
                        printf("failed to mmap\n");
                        break;
                }
                munmap(ptr, 4096 * 64);
                usleep(1);
                pptr = malloc(1);
                usleep(1);
                pptr[0] = 1;
                usleep(1);
                free(pptr);
                usleep(1);
                nanosleep(&ts, NULL);
        }
        close(fd);
        return NULL;
  }

  int main(int argc, char *argv[])
  {
        void *ptr;
        int i;
        pthread_t threads[THREAD_COUNT];

        if (argc < 2)
                return 0;

        filename = argv[1];

        for (i = 0; i < THREAD_COUNT; i++) {
                if (pthread_create(threads + i, NULL, worker, NULL)) {
                        fprintf(stderr, "Error creating thread\n");
                        return 0;
                }
        }

        for (i = 0; i < THREAD_COUNT; i++)
                pthread_join(threads[i], NULL);
        return 0;
  }
and the following command:
  1. run `stress_test /bin/ls` in one windown
  2. hack bcc trace.py with the following change:
     --- a/tools/trace.py
     +++ b/tools/trace.py
     @@ -513,6 +513,7 @@ BPF_PERF_OUTPUT(%s);
              __data.tgid = __tgid;
              __data.pid = __pid;
              bpf_get_current_comm(&__data.comm, sizeof(__data.comm));
     +        bpf_send_signal(10);
      %s
      %s
              %s.perf_submit(%s, &__data, sizeof(__data));
  3. in a different window run
     ./trace.py -p $(pidof stress_test) t:sched:sched_switch

The deadlock can be reproduced in our production system.

Similar to Song's fix, the fix is to delay sending signal if
irqs is disabled to avoid deadlocks involving with rq_lock.
With this change, my above stress-test in our production system
won't cause deadlock any more.

I also implemented a scale-down version of reproducer in the
selftest (a subsequent commit). With latest bpf-next,
it complains for the following potential deadlock.
  [   32.832450] -> #1 (&p->pi_lock){-.-.}:
  [   32.833100]        _raw_spin_lock_irqsave+0x44/0x80
  [   32.833696]        task_rq_lock+0x2c/0xa0
  [   32.834182]        task_sched_runtime+0x59/0xd0
  [   32.834721]        thread_group_cputime+0x250/0x270
  [   32.835304]        thread_group_cputime_adjusted+0x2e/0x70
  [   32.835959]        do_task_stat+0x8a7/0xb80
  [   32.836461]        proc_single_show+0x51/0xb0
  ...
  [   32.839512] -> #0 (&(&sighand->siglock)->rlock){....}:
  [   32.840275]        __lock_acquire+0x1358/0x1a20
  [   32.840826]        lock_acquire+0xc7/0x1d0
  [   32.841309]        _raw_spin_lock_irqsave+0x44/0x80
  [   32.841916]        __lock_task_sighand+0x79/0x160
  [   32.842465]        do_send_sig_info+0x35/0x90
  [   32.842977]        bpf_send_signal+0xa/0x10
  [   32.843464]        bpf_prog_bc13ed9e4d3163e3_send_signal_tp_sched+0x465/0x1000
  [   32.844301]        trace_call_bpf+0x115/0x270
  [   32.844809]        perf_trace_run_bpf_submit+0x4a/0xc0
  [   32.845411]        perf_trace_sched_switch+0x10f/0x180
  [   32.846014]        __schedule+0x45d/0x880
  [   32.846483]        schedule+0x5f/0xd0
  ...

  [   32.853148] Chain exists of:
  [   32.853148]   &(&sighand->siglock)->rlock --> &p->pi_lock --> &rq->lock
  [   32.853148]
  [   32.854451]  Possible unsafe locking scenario:
  [   32.854451]
  [   32.855173]        CPU0                    CPU1
  [   32.855745]        ----                    ----
  [   32.856278]   lock(&rq->lock);
  [   32.856671]                                lock(&p->pi_lock);
  [   32.857332]                                lock(&rq->lock);
  [   32.857999]   lock(&(&sighand->siglock)->rlock);

  Deadlock happens on CPU0 when it tries to acquire &sighand->siglock
  but it has been held by CPU1 and CPU1 tries to grab &rq->lock
  and cannot get it.

  This is not exactly the callstack in our production environment,
  but sympotom is similar and both locks are using spin_lock_irqsave()
  to acquire the lock, and both involves rq_lock. The fix to delay
  sending signal when irq is disabled also fixed this issue.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Cc: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20200304191104.2796501-1-yhs@fb.com
pcercuei pushed a commit to OpenDingux/linux that referenced this issue Nov 28, 2020
This fix is for a failure that occurred in the DWARF unwind perf test.

Stack unwinders may probe memory when looking for frames.

Memory sanitizer will poison and track uninitialized memory on the
stack, and on the heap if the value is copied to the heap.

This can lead to false memory sanitizer failures for the use of an
uninitialized value.

Avoid this problem by removing the poison on the copied stack.

The full msan failure with track origins looks like:

==2168==WARNING: MemorySanitizer: use-of-uninitialized-value
    #0 0x559ceb10755b in handle_cfi elfutils/libdwfl/frame_unwind.c:648:8
    #1 0x559ceb105448 in __libdwfl_frame_unwind elfutils/libdwfl/frame_unwind.c:741:4
    #2 0x559ceb0ece90 in dwfl_thread_getframes elfutils/libdwfl/dwfl_frame.c:435:7
    #3 0x559ceb0ec6b7 in get_one_thread_frames_cb elfutils/libdwfl/dwfl_frame.c:379:10
    #4 0x559ceb0ec6b7 in get_one_thread_cb elfutils/libdwfl/dwfl_frame.c:308:17
    #5 0x559ceb0ec6b7 in dwfl_getthreads elfutils/libdwfl/dwfl_frame.c:283:17
    #6 0x559ceb0ec6b7 in getthread elfutils/libdwfl/dwfl_frame.c:354:14
    #7 0x559ceb0ec6b7 in dwfl_getthread_frames elfutils/libdwfl/dwfl_frame.c:388:10
    #8 0x559ceaff6ae6 in unwind__get_entries tools/perf/util/unwind-libdw.c:236:8
    #9 0x559ceabc9dbc in test_dwarf_unwind__thread tools/perf/tests/dwarf-unwind.c:111:8
    #10 0x559ceabca5cf in test_dwarf_unwind__compare tools/perf/tests/dwarf-unwind.c:138:26
    #11 0x7f812a6865b0 in bsearch (libc.so.6+0x4e5b0)
    #12 0x559ceabca871 in test_dwarf_unwind__krava_3 tools/perf/tests/dwarf-unwind.c:162:2
    #13 0x559ceabca926 in test_dwarf_unwind__krava_2 tools/perf/tests/dwarf-unwind.c:169:9
    #14 0x559ceabca946 in test_dwarf_unwind__krava_1 tools/perf/tests/dwarf-unwind.c:174:9
    #15 0x559ceabcae12 in test__dwarf_unwind tools/perf/tests/dwarf-unwind.c:211:8
    MIPS#16 0x559ceabbc4ab in run_test tools/perf/tests/builtin-test.c:418:9
    MIPS#17 0x559ceabbc4ab in test_and_print tools/perf/tests/builtin-test.c:448:9
    MIPS#18 0x559ceabbac70 in __cmd_test tools/perf/tests/builtin-test.c:669:4
    MIPS#19 0x559ceabbac70 in cmd_test tools/perf/tests/builtin-test.c:815:9
    MIPS#20 0x559cea960e30 in run_builtin tools/perf/perf.c:313:11
    MIPS#21 0x559cea95fbce in handle_internal_command tools/perf/perf.c:365:8
    MIPS#22 0x559cea95fbce in run_argv tools/perf/perf.c:409:2
    MIPS#23 0x559cea95fbce in main tools/perf/perf.c:539:3

  Uninitialized value was stored to memory at
    #0 0x559ceb106acf in __libdwfl_frame_reg_set elfutils/libdwfl/frame_unwind.c:77:22
    #1 0x559ceb106acf in handle_cfi elfutils/libdwfl/frame_unwind.c:627:13
    #2 0x559ceb105448 in __libdwfl_frame_unwind elfutils/libdwfl/frame_unwind.c:741:4
    #3 0x559ceb0ece90 in dwfl_thread_getframes elfutils/libdwfl/dwfl_frame.c:435:7
    #4 0x559ceb0ec6b7 in get_one_thread_frames_cb elfutils/libdwfl/dwfl_frame.c:379:10
    #5 0x559ceb0ec6b7 in get_one_thread_cb elfutils/libdwfl/dwfl_frame.c:308:17
    #6 0x559ceb0ec6b7 in dwfl_getthreads elfutils/libdwfl/dwfl_frame.c:283:17
    #7 0x559ceb0ec6b7 in getthread elfutils/libdwfl/dwfl_frame.c:354:14
    #8 0x559ceb0ec6b7 in dwfl_getthread_frames elfutils/libdwfl/dwfl_frame.c:388:10
    #9 0x559ceaff6ae6 in unwind__get_entries tools/perf/util/unwind-libdw.c:236:8
    #10 0x559ceabc9dbc in test_dwarf_unwind__thread tools/perf/tests/dwarf-unwind.c:111:8
    #11 0x559ceabca5cf in test_dwarf_unwind__compare tools/perf/tests/dwarf-unwind.c:138:26
    #12 0x7f812a6865b0 in bsearch (libc.so.6+0x4e5b0)
    #13 0x559ceabca871 in test_dwarf_unwind__krava_3 tools/perf/tests/dwarf-unwind.c:162:2
    #14 0x559ceabca926 in test_dwarf_unwind__krava_2 tools/perf/tests/dwarf-unwind.c:169:9
    #15 0x559ceabca946 in test_dwarf_unwind__krava_1 tools/perf/tests/dwarf-unwind.c:174:9
    MIPS#16 0x559ceabcae12 in test__dwarf_unwind tools/perf/tests/dwarf-unwind.c:211:8
    MIPS#17 0x559ceabbc4ab in run_test tools/perf/tests/builtin-test.c:418:9
    MIPS#18 0x559ceabbc4ab in test_and_print tools/perf/tests/builtin-test.c:448:9
    MIPS#19 0x559ceabbac70 in __cmd_test tools/perf/tests/builtin-test.c:669:4
    MIPS#20 0x559ceabbac70 in cmd_test tools/perf/tests/builtin-test.c:815:9
    MIPS#21 0x559cea960e30 in run_builtin tools/perf/perf.c:313:11
    MIPS#22 0x559cea95fbce in handle_internal_command tools/perf/perf.c:365:8
    MIPS#23 0x559cea95fbce in run_argv tools/perf/perf.c:409:2
    MIPS#24 0x559cea95fbce in main tools/perf/perf.c:539:3

  Uninitialized value was stored to memory at
    #0 0x559ceb106a54 in handle_cfi elfutils/libdwfl/frame_unwind.c:613:9
    #1 0x559ceb105448 in __libdwfl_frame_unwind elfutils/libdwfl/frame_unwind.c:741:4
    #2 0x559ceb0ece90 in dwfl_thread_getframes elfutils/libdwfl/dwfl_frame.c:435:7
    #3 0x559ceb0ec6b7 in get_one_thread_frames_cb elfutils/libdwfl/dwfl_frame.c:379:10
    #4 0x559ceb0ec6b7 in get_one_thread_cb elfutils/libdwfl/dwfl_frame.c:308:17
    #5 0x559ceb0ec6b7 in dwfl_getthreads elfutils/libdwfl/dwfl_frame.c:283:17
    #6 0x559ceb0ec6b7 in getthread elfutils/libdwfl/dwfl_frame.c:354:14
    #7 0x559ceb0ec6b7 in dwfl_getthread_frames elfutils/libdwfl/dwfl_frame.c:388:10
    #8 0x559ceaff6ae6 in unwind__get_entries tools/perf/util/unwind-libdw.c:236:8
    #9 0x559ceabc9dbc in test_dwarf_unwind__thread tools/perf/tests/dwarf-unwind.c:111:8
    #10 0x559ceabca5cf in test_dwarf_unwind__compare tools/perf/tests/dwarf-unwind.c:138:26
    #11 0x7f812a6865b0 in bsearch (libc.so.6+0x4e5b0)
    #12 0x559ceabca871 in test_dwarf_unwind__krava_3 tools/perf/tests/dwarf-unwind.c:162:2
    #13 0x559ceabca926 in test_dwarf_unwind__krava_2 tools/perf/tests/dwarf-unwind.c:169:9
    #14 0x559ceabca946 in test_dwarf_unwind__krava_1 tools/perf/tests/dwarf-unwind.c:174:9
    #15 0x559ceabcae12 in test__dwarf_unwind tools/perf/tests/dwarf-unwind.c:211:8
    MIPS#16 0x559ceabbc4ab in run_test tools/perf/tests/builtin-test.c:418:9
    MIPS#17 0x559ceabbc4ab in test_and_print tools/perf/tests/builtin-test.c:448:9
    MIPS#18 0x559ceabbac70 in __cmd_test tools/perf/tests/builtin-test.c:669:4
    MIPS#19 0x559ceabbac70 in cmd_test tools/perf/tests/builtin-test.c:815:9
    MIPS#20 0x559cea960e30 in run_builtin tools/perf/perf.c:313:11
    MIPS#21 0x559cea95fbce in handle_internal_command tools/perf/perf.c:365:8
    MIPS#22 0x559cea95fbce in run_argv tools/perf/perf.c:409:2
    MIPS#23 0x559cea95fbce in main tools/perf/perf.c:539:3

  Uninitialized value was stored to memory at
    #0 0x559ceaff8800 in memory_read tools/perf/util/unwind-libdw.c:156:10
    #1 0x559ceb10f053 in expr_eval elfutils/libdwfl/frame_unwind.c:501:13
    #2 0x559ceb1060cc in handle_cfi elfutils/libdwfl/frame_unwind.c:603:18
    #3 0x559ceb105448 in __libdwfl_frame_unwind elfutils/libdwfl/frame_unwind.c:741:4
    #4 0x559ceb0ece90 in dwfl_thread_getframes elfutils/libdwfl/dwfl_frame.c:435:7
    #5 0x559ceb0ec6b7 in get_one_thread_frames_cb elfutils/libdwfl/dwfl_frame.c:379:10
    #6 0x559ceb0ec6b7 in get_one_thread_cb elfutils/libdwfl/dwfl_frame.c:308:17
    #7 0x559ceb0ec6b7 in dwfl_getthreads elfutils/libdwfl/dwfl_frame.c:283:17
    #8 0x559ceb0ec6b7 in getthread elfutils/libdwfl/dwfl_frame.c:354:14
    #9 0x559ceb0ec6b7 in dwfl_getthread_frames elfutils/libdwfl/dwfl_frame.c:388:10
    #10 0x559ceaff6ae6 in unwind__get_entries tools/perf/util/unwind-libdw.c:236:8
    #11 0x559ceabc9dbc in test_dwarf_unwind__thread tools/perf/tests/dwarf-unwind.c:111:8
    #12 0x559ceabca5cf in test_dwarf_unwind__compare tools/perf/tests/dwarf-unwind.c:138:26
    #13 0x7f812a6865b0 in bsearch (libc.so.6+0x4e5b0)
    #14 0x559ceabca871 in test_dwarf_unwind__krava_3 tools/perf/tests/dwarf-unwind.c:162:2
    #15 0x559ceabca926 in test_dwarf_unwind__krava_2 tools/perf/tests/dwarf-unwind.c:169:9
    MIPS#16 0x559ceabca946 in test_dwarf_unwind__krava_1 tools/perf/tests/dwarf-unwind.c:174:9
    MIPS#17 0x559ceabcae12 in test__dwarf_unwind tools/perf/tests/dwarf-unwind.c:211:8
    MIPS#18 0x559ceabbc4ab in run_test tools/perf/tests/builtin-test.c:418:9
    MIPS#19 0x559ceabbc4ab in test_and_print tools/perf/tests/builtin-test.c:448:9
    MIPS#20 0x559ceabbac70 in __cmd_test tools/perf/tests/builtin-test.c:669:4
    MIPS#21 0x559ceabbac70 in cmd_test tools/perf/tests/builtin-test.c:815:9
    MIPS#22 0x559cea960e30 in run_builtin tools/perf/perf.c:313:11
    MIPS#23 0x559cea95fbce in handle_internal_command tools/perf/perf.c:365:8
    MIPS#24 0x559cea95fbce in run_argv tools/perf/perf.c:409:2
    MIPS#25 0x559cea95fbce in main tools/perf/perf.c:539:3

  Uninitialized value was stored to memory at
    #0 0x559cea9027d9 in __msan_memcpy llvm/llvm-project/compiler-rt/lib/msan/msan_interceptors.cpp:1558:3
    #1 0x559cea9d2185 in sample_ustack tools/perf/arch/x86/tests/dwarf-unwind.c:41:2
    #2 0x559cea9d202c in test__arch_unwind_sample tools/perf/arch/x86/tests/dwarf-unwind.c:72:9
    #3 0x559ceabc9cbd in test_dwarf_unwind__thread tools/perf/tests/dwarf-unwind.c:106:6
    #4 0x559ceabca5cf in test_dwarf_unwind__compare tools/perf/tests/dwarf-unwind.c:138:26
    #5 0x7f812a6865b0 in bsearch (libc.so.6+0x4e5b0)
    #6 0x559ceabca871 in test_dwarf_unwind__krava_3 tools/perf/tests/dwarf-unwind.c:162:2
    #7 0x559ceabca926 in test_dwarf_unwind__krava_2 tools/perf/tests/dwarf-unwind.c:169:9
    #8 0x559ceabca946 in test_dwarf_unwind__krava_1 tools/perf/tests/dwarf-unwind.c:174:9
    #9 0x559ceabcae12 in test__dwarf_unwind tools/perf/tests/dwarf-unwind.c:211:8
    #10 0x559ceabbc4ab in run_test tools/perf/tests/builtin-test.c:418:9
    #11 0x559ceabbc4ab in test_and_print tools/perf/tests/builtin-test.c:448:9
    #12 0x559ceabbac70 in __cmd_test tools/perf/tests/builtin-test.c:669:4
    #13 0x559ceabbac70 in cmd_test tools/perf/tests/builtin-test.c:815:9
    #14 0x559cea960e30 in run_builtin tools/perf/perf.c:313:11
    #15 0x559cea95fbce in handle_internal_command tools/perf/perf.c:365:8
    MIPS#16 0x559cea95fbce in run_argv tools/perf/perf.c:409:2
    MIPS#17 0x559cea95fbce in main tools/perf/perf.c:539:3

  Uninitialized value was created by an allocation of 'bf' in the stack frame of function 'perf_event__synthesize_mmap_events'
    #0 0x559ceafc5f60 in perf_event__synthesize_mmap_events tools/perf/util/synthetic-events.c:445

SUMMARY: MemorySanitizer: use-of-uninitialized-value elfutils/libdwfl/frame_unwind.c:648:8 in handle_cfi
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: clang-built-linux@googlegroups.com
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sandeep Dasgupta <sdasgup@google.com>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20201113182053.754625-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
pcercuei pushed a commit to OpenDingux/linux that referenced this issue Aug 3, 2021
The problem occurs between dev_get_by_index() and dev_xdp_attach_link().
At this point, dev_xdp_uninstall() is called. Then xdp link will not be
detached automatically when dev is released. But link->dev already
points to dev, when xdp link is released, dev will still be accessed,
but dev has been released.

dev_get_by_index()        |
link->dev = dev           |
                          |      rtnl_lock()
                          |      unregister_netdevice_many()
                          |          dev_xdp_uninstall()
                          |      rtnl_unlock()
rtnl_lock();              |
dev_xdp_attach_link()     |
rtnl_unlock();            |
                          |      netdev_run_todo() // dev released
bpf_xdp_link_release()    |
    /* access dev.        |
       use-after-free */  |

[   45.966867] BUG: KASAN: use-after-free in bpf_xdp_link_release+0x3b8/0x3d0
[   45.967619] Read of size 8 at addr ffff00000f9980c8 by task a.out/732
[   45.968297]
[   45.968502] CPU: 1 PID: 732 Comm: a.out Not tainted 5.13.0+ MIPS#22
[   45.969222] Hardware name: linux,dummy-virt (DT)
[   45.969795] Call trace:
[   45.970106]  dump_backtrace+0x0/0x4c8
[   45.970564]  show_stack+0x30/0x40
[   45.970981]  dump_stack_lvl+0x120/0x18c
[   45.971470]  print_address_description.constprop.0+0x74/0x30c
[   45.972182]  kasan_report+0x1e8/0x200
[   45.972659]  __asan_report_load8_noabort+0x2c/0x50
[   45.973273]  bpf_xdp_link_release+0x3b8/0x3d0
[   45.973834]  bpf_link_free+0xd0/0x188
[   45.974315]  bpf_link_put+0x1d0/0x218
[   45.974790]  bpf_link_release+0x3c/0x58
[   45.975291]  __fput+0x20c/0x7e8
[   45.975706]  ____fput+0x24/0x30
[   45.976117]  task_work_run+0x104/0x258
[   45.976609]  do_notify_resume+0x894/0xaf8
[   45.977121]  work_pending+0xc/0x328
[   45.977575]
[   45.977775] The buggy address belongs to the page:
[   45.978369] page:fffffc00003e6600 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x4f998
[   45.979522] flags: 0x7fffe0000000000(node=0|zone=0|lastcpupid=0x3ffff)
[   45.980349] raw: 07fffe0000000000 fffffc00003e6708 ffff0000dac3c010 0000000000000000
[   45.981309] raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
[   45.982259] page dumped because: kasan: bad access detected
[   45.982948]
[   45.983153] Memory state around the buggy address:
[   45.983753]  ffff00000f997f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[   45.984645]  ffff00000f998000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[   45.985533] >ffff00000f998080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[   45.986419]                                               ^
[   45.987112]  ffff00000f998100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[   45.988006]  ffff00000f998180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[   45.988895] ==================================================================
[   45.989773] Disabling lock debugging due to kernel taint
[   45.990552] Kernel panic - not syncing: panic_on_warn set ...
[   45.991166] CPU: 1 PID: 732 Comm: a.out Tainted: G    B             5.13.0+ MIPS#22
[   45.991929] Hardware name: linux,dummy-virt (DT)
[   45.992448] Call trace:
[   45.992753]  dump_backtrace+0x0/0x4c8
[   45.993208]  show_stack+0x30/0x40
[   45.993627]  dump_stack_lvl+0x120/0x18c
[   45.994113]  dump_stack+0x1c/0x34
[   45.994530]  panic+0x3a4/0x7d8
[   45.994930]  end_report+0x194/0x198
[   45.995380]  kasan_report+0x134/0x200
[   45.995850]  __asan_report_load8_noabort+0x2c/0x50
[   45.996453]  bpf_xdp_link_release+0x3b8/0x3d0
[   45.997007]  bpf_link_free+0xd0/0x188
[   45.997474]  bpf_link_put+0x1d0/0x218
[   45.997942]  bpf_link_release+0x3c/0x58
[   45.998429]  __fput+0x20c/0x7e8
[   45.998833]  ____fput+0x24/0x30
[   45.999247]  task_work_run+0x104/0x258
[   45.999731]  do_notify_resume+0x894/0xaf8
[   46.000236]  work_pending+0xc/0x328
[   46.000697] SMP: stopping secondary CPUs
[   46.001226] Dumping ftrace buffer:
[   46.001663]    (ftrace buffer empty)
[   46.002110] Kernel Offset: disabled
[   46.002545] CPU features: 0x00000001,23202c00
[   46.003080] Memory Limit: none

Fixes: aa8d3a7 ("bpf, xdp: Add bpf_link-based XDP attachment API")
Reported-by: Abaci <abaci@linux.alibaba.com>
Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Dust Li <dust.li@linux.alibaba.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210710031635.41649-1-xuanzhuo@linux.alibaba.com
pcercuei pushed a commit to OpenDingux/linux that referenced this issue Nov 10, 2022
Tests for races between shinfo_cache (de)activation and hypercall+ioctl()
processing.  KVM has had bugs where activating the shared info cache
multiple times and/or with concurrent users results in lock corruption,
NULL pointer dereferences, and other fun.

For the timer injection testcase (MIPS#22), re-arm the timer until the IRQ
is successfully injected.  If the timer expires while the shared info
is deactivated (invalid), KVM will drop the event.

Signed-off-by: Michal Luczaj <mhal@rbox.co>
Co-developed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20221013211234.1318131-16-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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