Re: [syzbot] WARNING in huge_pmd_set_accessed

[Dmitry Vyukov]

On Fri, Mar 12, 2021 at 8:07 AM syzbot
<syzbot+edb1179c837e79cc2fc3@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
>
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit:    05a59d79 Merge git://git.kernel.org:/pub/scm/linux/kernel/..
> git tree:       upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=15b8820ad00000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=750735fdbc630971
> dashboard link: https://syzkaller.appspot.com/bug?extid=edb1179c837e79cc2fc3
>
> Unfortunately, I don't have any reproducer for this issue yet.
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+edb1179c837e79cc2fc3@xxxxxxxxxxxxxxxxxxxxxxxxx

Kernel produced corrupted output, there is actually kvm_wait frame.

#syz dup: WARNING in kvm_wait

> ------------[ cut here ]------------
> raw_local_irq_restore() called with IRQs enabled
> WARNING: CPU: 1 PID: 8400 at kernel/locking/irqflag-debug.c:10 warn_bogus_irq_restore+0x1d/0x20 kernel/locking/irqflag-debug.c:10
> Modules linked in:
> CPU: 1 PID: 8400 Comm: syz-fuzzer Not tainted 5.12.0-rc2-syzkaller #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
> RIP: 0010:warn_bogus_irq_restore+0x1d/0x20 kernel/locking/irqflag-debug.c:10
> Code: be ff cc cc cc cc cc cc cc cc cc cc cc 80 3d 11 d1 ad 04 00 74 01 c3 48 c7 c7 20 79 6b 89 c6 05 00 d1 ad 04 01 e8 75 5b be ff <0f> 0b c3 48 39 77 10 0f 84 97 00 00 00 66 f7 47 22 f0 ff 74 4b 48
> RSP: 0000:ffffc90001737ac8 EFLAGS: 00010282
> RAX: 0000000000000000 RBX: ffff88801992a840 RCX: 0000000000000000
> RDX: ffff8880223d0200 RSI: ffffffff815b4435 RDI: fffff520002e6f4b
> RBP: 0000000000000200 R08: 0000000000000000 R09: 0000000000000000
> R10: ffffffff815ad19e R11: 0000000000000000 R12: 0000000000000003
> R13: ffffed1003325508 R14: 0000000000000001 R15: ffff8880b9d36000
> FS:  000000c00002e890(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> Call Trace:
>  pv_wait arch/x86/include/asm/paravirt.h:564 [inline]
>  pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:470 [inline]
>  __pv_queued_spin_lock_slowpath+0x8b8/0xb40 kernel/locking/qspinlock.c:508
>  pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:554 [inline]
>  queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline]
>  queued_spin_lock include/asm-generic/qspinlock.h:85 [inline]
>  do_raw_spin_lock+0x200/0x2b0 kernel/locking/spinlock_debug.c:113
>  spin_lock include/linux/spinlock.h:354 [inline]
>  pmd_lock include/linux/mm.h:2264 [inline]
>  huge_pmd_set_accessed+0x103/0x320 mm/huge_memory.c:1265
>  handle_mm_fault+0x1bc/0x7e0 mm/memory.c:4549
>  handle_page_fault arch/x86/mm/fault.c:1475 [inline]
>  exc_page_fault+0x9e/0x180 arch/x86/mm/fault.c:1531
> RIP: 0033:0x59072c
> Code: 48 8d 05 97 25 3e 00 48 89 44 24 08 e8 6d 54 ea ff 90 e8 07 a1 ed ff eb a5 cc cc cc cc cc 8b 44 24 10 48 8b 4c 24 08 89 41 24 <c3> cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc 48 8b
> RSP: 002b:000000c0002e97b0 EFLAGS: 00010286
> RAX: 0000000000004ef5 RBX: 0000000000004ef5 RCX: 0000000000d85fe0
> RBP: 000000c0002e9890 R08: 0000000000004ef4 R09: 000000000059c5a0
> R13: 00aaaaaaaaaaaaaa R14: 000000000093f064 R15: 0000000000000038
>
>
> ---
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