[syzbot] WARNING in kvm_wait

[syzbot] WARNING in kvm_wait

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    a38fd874 Linux 5.12-rc2
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=14158fdad00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=db9c6adb4986f2f2
dashboard link: https://syzkaller.appspot.com/bug?extid=3c2bc6358072ede0f11b
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1096d35cd00000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=16bf1e52d00000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+3c2bc6358072ede0f11b@syzkaller.appspotmail.com

------------[ cut here ]------------
raw_local_irq_restore() called with IRQs enabled
WARNING: CPU: 0 PID: 14236 at kernel/locking/irqflag-debug.c:10 warn_bogus_irq_restore+0x1d/0x20 kernel/locking/irqflag-debug.c:10
Modules linked in:
CPU: 0 PID: 14236 Comm: syz-executor143 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 ac 2b b0 04 00 74 01 c3 48 c7 c7 a0 8f 6b 89 c6 05 9b 2b b0 04 01 e8 f7 cb 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: 0018:ffffc9000c29f9c0 EFLAGS: 00010286
RAX: 0000000000000000 RBX: ffffc90000e1b688 RCX: 0000000000000000
RDX: ffff88801e689bc0 RSI: ffffffff815c0eb5 RDI: fffff52001853f2a
RBP: 0000000000000200 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff815b9c4e R11: 0000000000000000 R12: 0000000000000003
R13: fffff520001c36d1 R14: 0000000000000001 R15: ffff8880b9c35f40
FS:  00000000018ce300(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffd79af41d8 CR3: 000000001c373000 CR4: 0000000000350ef0
Call Trace:
 kvm_wait arch/x86/kernel/kvm.c:860 [inline]
 kvm_wait+0xc9/0xe0 arch/x86/kernel/kvm.c:837
 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]
 futex_wake+0x1b5/0x490 kernel/futex.c:1610
 do_futex+0x326/0x1710 kernel/futex.c:3740
 __do_sys_futex+0x2a2/0x470 kernel/futex.c:3798
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x4459c9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 11 15 00 00 90 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 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffd79af41f8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000004459c9
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00000000004ca408
RBP: 00000000004ca400 R08: 0000000000000000 R09: 0000000000000000
R10: 00007ffd79bec090 R11: 0000000000000246 R12: 00007ffd79af4230
R13: 00000000004ca40c R14: 0000000000000001 R15: 00000000004023b0


---
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Re: [syzbot] WARNING in kvm_wait

[Sean Christopherson]

On Mon, Mar 08, 2021, syzbot wrote:
> Hello,
> 
> syzbot found the following issue on:
> 
> HEAD commit:    a38fd874 Linux 5.12-rc2
> git tree:       upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=14158fdad00000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=db9c6adb4986f2f2
> dashboard link: https://syzkaller.appspot.com/bug?extid=3c2bc6358072ede0f11b
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1096d35cd00000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=16bf1e52d00000
> 
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+3c2bc6358072ede0f11b@syzkaller.appspotmail.com

Wanpeng has a patch posted to fix this[*], is there a way to retroactively point
syzbot at that fix?

[*] https://lkml.kernel.org/r/1614057902-23774-1-git-send-email-wanpengli@tencent.com

Re: [syzbot] WARNING in kvm_wait

[Dmitry Vyukov]

On Tue, Mar 9, 2021 at 12:29 AM 'Sean Christopherson' via
syzkaller-bugs <syzkaller-bugs@googlegroups.com> wrote:
>
> On Mon, Mar 08, 2021, syzbot wrote:
> > Hello,
> >
> > syzbot found the following issue on:
> >
> > HEAD commit:    a38fd874 Linux 5.12-rc2
> > git tree:       upstream
> > console output: https://syzkaller.appspot.com/x/log.txt?x=14158fdad00000
> > kernel config:  https://syzkaller.appspot.com/x/.config?x=db9c6adb4986f2f2
> > dashboard link: https://syzkaller.appspot.com/bug?extid=3c2bc6358072ede0f11b
> > syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1096d35cd00000
> > C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=16bf1e52d00000
> >
> > IMPORTANT: if you fix the issue, please add the following tag to the commit:
> > Reported-by: syzbot+3c2bc6358072ede0f11b@syzkaller.appspotmail.com
>
> Wanpeng has a patch posted to fix this[*], is there a way to retroactively point
> syzbot at that fix?
>
> [*] https://lkml.kernel.org/r/1614057902-23774-1-git-send-email-wanpengli@tencent.com

Great! Yes, it can be communicated to syzbot with:

#syz fix: x86/kvm: Fix broken irq restoration in kvm_wait

For details see: http://bit.do/syzbot#communication-with-syzbot