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unlink_anon_vmas: Unable to handle kernel paging request at virtual address 12005452 #102

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amboar opened this issue Aug 26, 2016 · 1 comment

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@amboar
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amboar commented Aug 26, 2016

Same kernel/qemu configuration as #101, but with a different backtrace:

Unable to handle kernel paging request at virtual address 12005452
pgd = c0004000
[12005452] *pgd=00000000
Internal error: Oops: 5 [#1] ARM
Modules linked in:
CPU: 0 PID: 614 Comm: syslogd Not tainted 4.7.1-00053-g6d93f625315a #581
Hardware name: ASpeed SoC
task: de7d20a0 ti: c8f7a000 task.ti: c8f7a000
PC is at unlink_anon_vmas+0xd0/0x198
LR is at 0xc8f70700
pc : [<c019f1f4>]    lr : [<c8f70700>]    psr: 60000013
sp : c8f7bda0  ip : 00000000  fp : 00000001
r10: c0720f79  r9 : c8f68bb0  r8 : c8c838c0
r7 : c8c838c0  r6 : c8f68bec  r5 : 1200544a  r4 : c8f70700
r3 : 00000001  r2 : c8c838c0  r1 : c8c8390c  r0 : 00000000
Flags: nZCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment none
Control: 00093177  Table: 48f8c000  DAC: 00000051
Process syslogd (pid: 614, stack limit = 0xc8f7a190)
Stack: (0xc8f7bda0 to 0xc8f7c000)
bda0: c8f68bb0 20000013 c8f72e00 c8f68bb0 c8f6e738 c8f7bdfc 00002000 00000000
bdc0: b6f69000 c8f68bb0 c8da67c0 c01949f4 b6f69000 c8f688f0 c8f688f0 c8f72e00
bde0: c0702028 c8f7be74 00000000 c8f72e54 c8d7bc80 c019addc de7d20a0 c8f72e00
be00: 00000001 00000000 00000000 ffffffff 00000000 00000000 0000019a 00000400
be20: dbcc3000 00000000 00000000 60000013 de7d2428 de7d20c0 c8da67c0 de7d23c4
be40: c8f72e00 8a043988 c8f72e00 00000000 de7d23c4 c010cf94 de7d20a0 c8f72e00
be60: de7d23c4 c01103ec 0000000f de7d2420 de7d20a0 00000004 c8d7bc80 8a043988
be80: 0000000f ffffe000 c8da67c0 c01118f8 00000009 c8f7a000 00418004 c8f7bee4
bea0: c8da6cc4 c011a9cc de7d20a0 60000013 de7d2428 de7d20c0 20000013 00000000
bec0: 4809d5d4 c8f7bfb0 c0702028 00000000 4809d5d8 00000000 000ab97c c01048c8
bee0: 00000000 00000000 c0119b14 60000093 00000001 c0702028 00000009 00000000
bf00: 00000000 00000000 00000000 0000000f 00000000 fffffffa 00000266 00000000
bf20: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
bf40: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
bf60: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 8a043988
bf80: c01025a4 c8f7a000 c8f7bfb0 0000010c c01025a4 c8f7a000 00000000 c0104d74
bfa0: 0000000f 00cdc008 0000003d c0102450 00000000 00000266 0000000f 00000000
bfc0: 0000000f 00cdc008 0000003d 0000010c 00cdc164 0000003d 00cdc264 000ab97c
bfe0: 000a911c bee2dc58 4809d5b0 4809d5d8 60000010 00000266 e7fddef0 e7fddef0
[<c019f1f4>] (unlink_anon_vmas) from [<c01949f4>] (free_pgtables+0x2c/0x98)
[<c01949f4>] (free_pgtables) from [<c019addc>] (exit_mmap+0xe8/0x200)
[<c019addc>] (exit_mmap) from [<c010cf94>] (mmput+0x30/0xc4)
[<c010cf94>] (mmput) from [<c01103ec>] (do_exit+0x34c/0x848)
[<c01103ec>] (do_exit) from [<c01118f8>] (do_group_exit+0x48/0xbc)
[<c011a9cc>] (get_signal) from [<c01048c8>] (do_signal+0x98/0x3dc)
[<c01048c8>] (do_signal) from [<c0104d74>] (do_work_pending+0x5c/0xc0)
[<c0104d74>] (do_work_pending) from [<c0102450>] (slow_work_pending+0xc/0x20)
Code: e5843008 e3a03c02 e584300c ebfffb7e (e5952008) 
---[ end trace 6acdac20fd3b07ef ]---
Fixing recursive fault but reboot is needed!
@legoater
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legoater commented Jul 7, 2017

moved to openbmc/qemu openbmc/qemu#9

@legoater legoater closed this as completed Jul 7, 2017
shenki pushed a commit that referenced this issue Jun 12, 2019
commit 5cdb0ef upstream.

In case USB disconnect happens at the moment transmitting workqueue is in
progress the underlying interface may be gone causing a NULL pointer
dereference. Add synchronization of the workqueue destruction with the
detach implementation in core so that the transmitting workqueue is stopped
during detach before the interfaces are removed.

Fix following Oops:

Unable to handle kernel NULL pointer dereference at virtual address 00000008
pgd = 9e6a802d
[00000008] *pgd=00000000
Internal error: Oops: 5 [#1] PREEMPT SMP ARM
Modules linked in: nf_log_ipv4 nf_log_common xt_LOG xt_limit iptable_mangle
xt_connmark xt_tcpudp xt_conntrack nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4
iptable_filter ip_tables x_tables usb_f_mass_storage usb_f_rndis u_ether
usb_serial_simple usbserial cdc_acm brcmfmac brcmutil smsc95xx usbnet
ci_hdrc_imx ci_hdrc ulpi usbmisc_imx 8250_exar 8250_pci 8250 8250_base
libcomposite configfs udc_core
CPU: 0 PID: 7 Comm: kworker/u8:0 Not tainted 4.19.23-00076-g03740aa-dirty #102
Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree)
Workqueue: brcmf_fws_wq brcmf_fws_dequeue_worker [brcmfmac]
PC is at brcmf_txfinalize+0x34/0x90 [brcmfmac]
LR is at brcmf_fws_dequeue_worker+0x218/0x33c [brcmfmac]
pc : [<7f0dee64>]    lr : [<7f0e4140>]    psr: 60010093
sp : ee8abef0  ip : 00000000  fp : edf38000
r10: ffffffed  r9 : edf38970  r8 : edf3800
r7 : edf3e970  r6 : 00000000  r5 : ede69000  r4 : 00000000
r3 : 00000a97  r2 : 00000000  r1 : 0000888e  r0 : ede69000
Flags: nZCv  IRQs off  FIQs on  Mode SVC_32  ISA ARM  Segment none
Control: 10c5387d  Table: 7d03c04a  DAC: 00000051
Process kworker/u8:0 (pid: 7, stack limit = 0x24ec3e04)
Stack: (0xee8abef0 to 0xee8ac000)
bee0:                                     ede69000 00000000 ed56c3e0 7f0e4140
bf00: 00000001 00000000 edf3800 edf3e99c ed56c3e0 80d03d00 edfea43a edf3e970
bf20: ee809880 ee804200 ee971100 00000000 edf3e974 00000000 ee804200 80135a70
bf40: 80d03d00 ee804218 ee809880 ee809894 ee804200 80d03d00 ee804218 ee8aa000
bf60: 00000088 80135d5c 00000000 ee829f00 ee829dc0 00000000 ee809880 80135d30
bf80: ee829f1c ee873eac 00000000 8013b1a0 ee829dc0 8013b07c 00000000 00000000
bfa0: 00000000 00000000 00000000 801010e8 00000000 00000000 00000000 00000000
bfc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
bfe0: 00000000 00000000 00000000 00000000 00000013 00000000 00000000 00000000
[<7f0dee64>] (brcmf_txfinalize [brcmfmac]) from [<7f0e4140>] (brcmf_fws_dequeue_worker+0x218/0x33c [brcmfmac])
[<7f0e4140>] (brcmf_fws_dequeue_worker [brcmfmac]) from [<80135a70>] (process_one_work+0x138/0x3f8)
[<80135a70>] (process_one_work) from [<80135d5c>] (worker_thread+0x2c/0x554)
[<80135d5c>] (worker_thread) from [<8013b1a0>] (kthread+0x124/0x154)
[<8013b1a0>] (kthread) from [<801010e8>] (ret_from_fork+0x14/0x2c)
Exception stack(0xee8abfb0 to 0xee8abff8)
bfa0:                                     00000000 00000000 00000000 00000000
bfc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
bfe0: 00000000 00000000 00000000 00000000 00000013 00000000
Code: e1530001 0a000007 e3560000 e1a00005 (05942008)
---[ end trace 079239dd31c86e90 ]---

Signed-off-by: Piotr Figiel <p.figiel@camlintechnologies.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
amboar pushed a commit to amboar/linux that referenced this issue Nov 26, 2020
[ Upstream commit 49d11be ]

I got the following lockdep splat with tree locks converted to rwsem
patches on btrfs/104:

  ======================================================
  WARNING: possible circular locking dependency detected
  5.9.0+ openbmc#102 Not tainted
  ------------------------------------------------------
  btrfs-cleaner/903 is trying to acquire lock:
  ffff8e7fab6ffe30 (btrfs-root-00){++++}-{3:3}, at: __btrfs_tree_read_lock+0x32/0x170

  but task is already holding lock:
  ffff8e7fab628a88 (&fs_info->commit_root_sem){++++}-{3:3}, at: btrfs_find_all_roots+0x41/0x80

  which lock already depends on the new lock.

  the existing dependency chain (in reverse order) is:

  -> openbmc#3 (&fs_info->commit_root_sem){++++}-{3:3}:
	 down_read+0x40/0x130
	 caching_thread+0x53/0x5a0
	 btrfs_work_helper+0xfa/0x520
	 process_one_work+0x238/0x540
	 worker_thread+0x55/0x3c0
	 kthread+0x13a/0x150
	 ret_from_fork+0x1f/0x30

  -> openbmc#2 (&caching_ctl->mutex){+.+.}-{3:3}:
	 __mutex_lock+0x7e/0x7b0
	 btrfs_cache_block_group+0x1e0/0x510
	 find_free_extent+0xb6e/0x12f0
	 btrfs_reserve_extent+0xb3/0x1b0
	 btrfs_alloc_tree_block+0xb1/0x330
	 alloc_tree_block_no_bg_flush+0x4f/0x60
	 __btrfs_cow_block+0x11d/0x580
	 btrfs_cow_block+0x10c/0x220
	 commit_cowonly_roots+0x47/0x2e0
	 btrfs_commit_transaction+0x595/0xbd0
	 sync_filesystem+0x74/0x90
	 generic_shutdown_super+0x22/0x100
	 kill_anon_super+0x14/0x30
	 btrfs_kill_super+0x12/0x20
	 deactivate_locked_super+0x36/0xa0
	 cleanup_mnt+0x12d/0x190
	 task_work_run+0x5c/0xa0
	 exit_to_user_mode_prepare+0x1df/0x200
	 syscall_exit_to_user_mode+0x54/0x280
	 entry_SYSCALL_64_after_hwframe+0x44/0xa9

  -> openbmc#1 (&space_info->groups_sem){++++}-{3:3}:
	 down_read+0x40/0x130
	 find_free_extent+0x2ed/0x12f0
	 btrfs_reserve_extent+0xb3/0x1b0
	 btrfs_alloc_tree_block+0xb1/0x330
	 alloc_tree_block_no_bg_flush+0x4f/0x60
	 __btrfs_cow_block+0x11d/0x580
	 btrfs_cow_block+0x10c/0x220
	 commit_cowonly_roots+0x47/0x2e0
	 btrfs_commit_transaction+0x595/0xbd0
	 sync_filesystem+0x74/0x90
	 generic_shutdown_super+0x22/0x100
	 kill_anon_super+0x14/0x30
	 btrfs_kill_super+0x12/0x20
	 deactivate_locked_super+0x36/0xa0
	 cleanup_mnt+0x12d/0x190
	 task_work_run+0x5c/0xa0
	 exit_to_user_mode_prepare+0x1df/0x200
	 syscall_exit_to_user_mode+0x54/0x280
	 entry_SYSCALL_64_after_hwframe+0x44/0xa9

  -> #0 (btrfs-root-00){++++}-{3:3}:
	 __lock_acquire+0x1167/0x2150
	 lock_acquire+0xb9/0x3d0
	 down_read_nested+0x43/0x130
	 __btrfs_tree_read_lock+0x32/0x170
	 __btrfs_read_lock_root_node+0x3a/0x50
	 btrfs_search_slot+0x614/0x9d0
	 btrfs_find_root+0x35/0x1b0
	 btrfs_read_tree_root+0x61/0x120
	 btrfs_get_root_ref+0x14b/0x600
	 find_parent_nodes+0x3e6/0x1b30
	 btrfs_find_all_roots_safe+0xb4/0x130
	 btrfs_find_all_roots+0x60/0x80
	 btrfs_qgroup_trace_extent_post+0x27/0x40
	 btrfs_add_delayed_data_ref+0x3fd/0x460
	 btrfs_free_extent+0x42/0x100
	 __btrfs_mod_ref+0x1d7/0x2f0
	 walk_up_proc+0x11c/0x400
	 walk_up_tree+0xf0/0x180
	 btrfs_drop_snapshot+0x1c7/0x780
	 btrfs_clean_one_deleted_snapshot+0xfb/0x110
	 cleaner_kthread+0xd4/0x140
	 kthread+0x13a/0x150
	 ret_from_fork+0x1f/0x30

  other info that might help us debug this:

  Chain exists of:
    btrfs-root-00 --> &caching_ctl->mutex --> &fs_info->commit_root_sem

   Possible unsafe locking scenario:

	 CPU0                    CPU1
	 ----                    ----
    lock(&fs_info->commit_root_sem);
				 lock(&caching_ctl->mutex);
				 lock(&fs_info->commit_root_sem);
    lock(btrfs-root-00);

   *** DEADLOCK ***

  3 locks held by btrfs-cleaner/903:
   #0: ffff8e7fab628838 (&fs_info->cleaner_mutex){+.+.}-{3:3}, at: cleaner_kthread+0x6e/0x140
   openbmc#1: ffff8e7faadac640 (sb_internal){.+.+}-{0:0}, at: start_transaction+0x40b/0x5c0
   openbmc#2: ffff8e7fab628a88 (&fs_info->commit_root_sem){++++}-{3:3}, at: btrfs_find_all_roots+0x41/0x80

  stack backtrace:
  CPU: 0 PID: 903 Comm: btrfs-cleaner Not tainted 5.9.0+ openbmc#102
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-2.fc32 04/01/2014
  Call Trace:
   dump_stack+0x8b/0xb0
   check_noncircular+0xcf/0xf0
   __lock_acquire+0x1167/0x2150
   ? __bfs+0x42/0x210
   lock_acquire+0xb9/0x3d0
   ? __btrfs_tree_read_lock+0x32/0x170
   down_read_nested+0x43/0x130
   ? __btrfs_tree_read_lock+0x32/0x170
   __btrfs_tree_read_lock+0x32/0x170
   __btrfs_read_lock_root_node+0x3a/0x50
   btrfs_search_slot+0x614/0x9d0
   ? find_held_lock+0x2b/0x80
   btrfs_find_root+0x35/0x1b0
   ? do_raw_spin_unlock+0x4b/0xa0
   btrfs_read_tree_root+0x61/0x120
   btrfs_get_root_ref+0x14b/0x600
   find_parent_nodes+0x3e6/0x1b30
   btrfs_find_all_roots_safe+0xb4/0x130
   btrfs_find_all_roots+0x60/0x80
   btrfs_qgroup_trace_extent_post+0x27/0x40
   btrfs_add_delayed_data_ref+0x3fd/0x460
   btrfs_free_extent+0x42/0x100
   __btrfs_mod_ref+0x1d7/0x2f0
   walk_up_proc+0x11c/0x400
   walk_up_tree+0xf0/0x180
   btrfs_drop_snapshot+0x1c7/0x780
   ? btrfs_clean_one_deleted_snapshot+0x73/0x110
   btrfs_clean_one_deleted_snapshot+0xfb/0x110
   cleaner_kthread+0xd4/0x140
   ? btrfs_alloc_root+0x50/0x50
   kthread+0x13a/0x150
   ? kthread_create_worker_on_cpu+0x40/0x40
   ret_from_fork+0x1f/0x30
  BTRFS info (device sdb): disk space caching is enabled
  BTRFS info (device sdb): has skinny extents

This happens because qgroups does a backref lookup when we create a
delayed ref.  From here it may have to look up a root from an indirect
ref, which does a normal lookup on the tree_root, which takes the read
lock on the tree_root nodes.

To fix this we need to add a variant for looking up roots that searches
the commit root of the tree_root.  Then when we do the backref search
using the commit root we are sure to not take any locks on the tree_root
nodes.  This gets rid of the lockdep splat when running btrfs/104.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
shenki pushed a commit that referenced this issue Jul 16, 2021
[ Upstream commit 45c8ddd ]

Before referencing 'host->data', the driver needs to check whether it is
null pointer, otherwise it will cause a null pointer reference.

This log reveals it:

[   29.355199] BUG: kernel NULL pointer dereference, address:
0000000000000014
[   29.357323] #PF: supervisor write access in kernel mode
[   29.357706] #PF: error_code(0x0002) - not-present page
[   29.358088] PGD 0 P4D 0
[   29.358280] Oops: 0002 [#1] PREEMPT SMP PTI
[   29.358595] CPU: 2 PID: 0 Comm: swapper/2 Not tainted 5.12.4-
g70e7f0549188-dirty #102
[   29.359164] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009),
BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014
[   29.359978] RIP: 0010:via_sdc_isr+0x21f/0x410
[   29.360314] Code: ff ff e8 84 aa d0 fd 66 45 89 7e 28 66 41 f7 c4 00
10 75 56 e8 72 aa d0 fd 66 41 f7 c4 00 c0 74 10 e8 65 aa d0 fd 48 8b 43
18 <c7> 40 14 ac ff ff ff e8 55 aa d0 fd 48 89 df e8 ad fb ff ff e9 77
[   29.361661] RSP: 0018:ffffc90000118e98 EFLAGS: 00010046
[   29.362042] RAX: 0000000000000000 RBX: ffff888107d77880
RCX: 0000000000000000
[   29.362564] RDX: 0000000000000000 RSI: ffffffff835d20bb
RDI: 00000000ffffffff
[   29.363085] RBP: ffffc90000118ed8 R08: 0000000000000001
R09: 0000000000000001
[   29.363604] R10: 0000000000000000 R11: 0000000000000001
R12: 0000000000008600
[   29.364128] R13: ffff888107d779c8 R14: ffffc90009c00200
R15: 0000000000008000
[   29.364651] FS:  0000000000000000(0000) GS:ffff88817bc80000(0000)
knlGS:0000000000000000
[   29.365235] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   29.365655] CR2: 0000000000000014 CR3: 0000000005a2e000
CR4: 00000000000006e0
[   29.366170] DR0: 0000000000000000 DR1: 0000000000000000
DR2: 0000000000000000
[   29.366683] DR3: 0000000000000000 DR6: 00000000fffe0ff0
DR7: 0000000000000400
[   29.367197] Call Trace:
[   29.367381]  <IRQ>
[   29.367537]  __handle_irq_event_percpu+0x53/0x3e0
[   29.367916]  handle_irq_event_percpu+0x35/0x90
[   29.368247]  handle_irq_event+0x39/0x60
[   29.368632]  handle_fasteoi_irq+0xc2/0x1d0
[   29.368950]  __common_interrupt+0x7f/0x150
[   29.369254]  common_interrupt+0xb4/0xd0
[   29.369547]  </IRQ>
[   29.369708]  asm_common_interrupt+0x1e/0x40
[   29.370016] RIP: 0010:native_safe_halt+0x17/0x20
[   29.370360] Code: 07 0f 00 2d db 80 43 00 f4 5d c3 0f 1f 84 00 00 00
00 00 8b 05 c2 37 e5 01 55 48 89 e5 85 c0 7e 07 0f 00 2d bb 80 43 00 fb
f4 <5d> c3 cc cc cc cc cc cc cc 55 48 89 e5 e8 67 53 ff ff 8b 0d f9 91
[   29.371696] RSP: 0018:ffffc9000008fe90 EFLAGS: 00000246
[   29.372079] RAX: 0000000000000000 RBX: 0000000000000002
RCX: 0000000000000000
[   29.372595] RDX: 0000000000000000 RSI: ffffffff854f67a4
RDI: ffffffff85403406
[   29.373122] RBP: ffffc9000008fe90 R08: 0000000000000001
R09: 0000000000000001
[   29.373646] R10: 0000000000000000 R11: 0000000000000001
R12: ffffffff86009188
[   29.374160] R13: 0000000000000000 R14: 0000000000000000
R15: ffff888100258000
[   29.374690]  default_idle+0x9/0x10
[   29.374944]  arch_cpu_idle+0xa/0x10
[   29.375198]  default_idle_call+0x6e/0x250
[   29.375491]  do_idle+0x1f0/0x2d0
[   29.375740]  cpu_startup_entry+0x18/0x20
[   29.376034]  start_secondary+0x11f/0x160
[   29.376328]  secondary_startup_64_no_verify+0xb0/0xbb
[   29.376705] Modules linked in:
[   29.376939] Dumping ftrace buffer:
[   29.377187]    (ftrace buffer empty)
[   29.377460] CR2: 0000000000000014
[   29.377712] ---[ end trace 51a473dffb618c47 ]---
[   29.378056] RIP: 0010:via_sdc_isr+0x21f/0x410
[   29.378380] Code: ff ff e8 84 aa d0 fd 66 45 89 7e 28 66 41 f7 c4 00
10 75 56 e8 72 aa d0 fd 66 41 f7 c4 00 c0 74 10 e8 65 aa d0 fd 48 8b 43
18 <c7> 40 14 ac ff ff ff e8 55 aa d0 fd 48 89 df e8 ad fb ff ff e9 77
[   29.379714] RSP: 0018:ffffc90000118e98 EFLAGS: 00010046
[   29.380098] RAX: 0000000000000000 RBX: ffff888107d77880
RCX: 0000000000000000
[   29.380614] RDX: 0000000000000000 RSI: ffffffff835d20bb
RDI: 00000000ffffffff
[   29.381134] RBP: ffffc90000118ed8 R08: 0000000000000001
R09: 0000000000000001
[   29.381653] R10: 0000000000000000 R11: 0000000000000001
R12: 0000000000008600
[   29.382176] R13: ffff888107d779c8 R14: ffffc90009c00200
R15: 0000000000008000
[   29.382697] FS:  0000000000000000(0000) GS:ffff88817bc80000(0000)
knlGS:0000000000000000
[   29.383277] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   29.383697] CR2: 0000000000000014 CR3: 0000000005a2e000
CR4: 00000000000006e0
[   29.384223] DR0: 0000000000000000 DR1: 0000000000000000
DR2: 0000000000000000
[   29.384736] DR3: 0000000000000000 DR6: 00000000fffe0ff0
DR7: 0000000000000400
[   29.385260] Kernel panic - not syncing: Fatal exception in interrupt
[   29.385882] Dumping ftrace buffer:
[   29.386135]    (ftrace buffer empty)
[   29.386401] Kernel Offset: disabled
[   29.386656] Rebooting in 1 seconds..

Signed-off-by: Zheyu Ma <zheyuma97@gmail.com>
Link: https://lore.kernel.org/r/1622727200-15808-1-git-send-email-zheyuma97@gmail.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
shenki pushed a commit that referenced this issue Aug 4, 2022
[ Upstream commit 56961c6 ]

Commit a7259df ("memblock: make memblock_find_in_range method
private") changed the API using which memory is reserved for the pKVM
hypervisor. However, memblock_phys_alloc() differs from the original API in
terms of kmemleak semantics -- the old one didn't report the reserved
regions to kmemleak while the new one does. Unfortunately, when protected
KVM is enabled, all kernel accesses to pKVM-private memory result in a
fatal exception, which can now happen because of kmemleak scans:

$ echo scan > /sys/kernel/debug/kmemleak
[   34.991354] kvm [304]: nVHE hyp BUG at: [<ffff800008fa3750>] __kvm_nvhe_handle_host_mem_abort+0x270/0x290!
[   34.991580] kvm [304]: Hyp Offset: 0xfffe8be807e00000
[   34.991813] Kernel panic - not syncing: HYP panic:
[   34.991813] PS:600003c9 PC:0000f418011a3750 ESR:00000000f2000800
[   34.991813] FAR:ffff000439200000 HPFAR:0000000004792000 PAR:0000000000000000
[   34.991813] VCPU:0000000000000000
[   34.993660] CPU: 0 PID: 304 Comm: bash Not tainted 5.19.0-rc2 #102
[   34.994059] Hardware name: linux,dummy-virt (DT)
[   34.994452] Call trace:
[   34.994641]  dump_backtrace.part.0+0xcc/0xe0
[   34.994932]  show_stack+0x18/0x6c
[   34.995094]  dump_stack_lvl+0x68/0x84
[   34.995276]  dump_stack+0x18/0x34
[   34.995484]  panic+0x16c/0x354
[   34.995673]  __hyp_pgtable_total_pages+0x0/0x60
[   34.995933]  scan_block+0x74/0x12c
[   34.996129]  scan_gray_list+0xd8/0x19c
[   34.996332]  kmemleak_scan+0x2c8/0x580
[   34.996535]  kmemleak_write+0x340/0x4a0
[   34.996744]  full_proxy_write+0x60/0xbc
[   34.996967]  vfs_write+0xc4/0x2b0
[   34.997136]  ksys_write+0x68/0xf4
[   34.997311]  __arm64_sys_write+0x20/0x2c
[   34.997532]  invoke_syscall+0x48/0x114
[   34.997779]  el0_svc_common.constprop.0+0x44/0xec
[   34.998029]  do_el0_svc+0x2c/0xc0
[   34.998205]  el0_svc+0x2c/0x84
[   34.998421]  el0t_64_sync_handler+0xf4/0x100
[   34.998653]  el0t_64_sync+0x18c/0x190
[   34.999252] SMP: stopping secondary CPUs
[   35.000034] Kernel Offset: disabled
[   35.000261] CPU features: 0x800,00007831,00001086
[   35.000642] Memory Limit: none
[   35.001329] ---[ end Kernel panic - not syncing: HYP panic:
[   35.001329] PS:600003c9 PC:0000f418011a3750 ESR:00000000f2000800
[   35.001329] FAR:ffff000439200000 HPFAR:0000000004792000 PAR:0000000000000000
[   35.001329] VCPU:0000000000000000 ]---

Fix this by explicitly excluding the hypervisor's memory pool from
kmemleak like we already do for the hyp BSS.

Cc: Mike Rapoport <rppt@kernel.org>
Fixes: a7259df ("memblock: make memblock_find_in_range method private")
Signed-off-by: Quentin Perret <qperret@google.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220616161135.3997786-1-qperret@google.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
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