Re: WARNING in do_debug

[Wanpeng Li]

2017-12-26 8:22 GMT+08:00 syzbot
<syzbot+adbefe6736a5b37af36f19ebfa8764fcdd9ddaed@xxxxxxxxxxxxxxxxxxxxxxxxx>:
> syzkaller has found reproducer for the following crash on
> 464e1d5f23cca236b930ef068c328a64cab78fb1
> git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/master
> compiler: gcc (GCC) 7.1.1 20170620
> .config is attached
> Raw console output is attached.
> C reproducer is attached
> syzkaller reproducer is attached. See https://goo.gl/kgGztJ
> for information about syzkaller reproducers
>

https://git.kernel.org/pub/scm/virt/kvm/kvm.git/commit/?h=queue&id=ed3b37ac63a060bdc184d126c0655c1af8b6de62

There is a fix in kvm/queue.

Regards,
Wanpeng Li

>
> WARNING: CPU: 0 PID: 3356 at arch/x86/kernel/traps.c:801
> cond_local_irq_disable arch/x86/kernel/traps.c:86 [inline]
> WARNING: CPU: 0 PID: 3356 at arch/x86/kernel/traps.c:801
> do_debug+0x4d8/0x6e0 arch/x86/kernel/traps.c:815
> Kernel panic - not syncing: panic_on_warn set ...
>
> CPU: 0 PID: 3356 Comm: syzkaller834441 Not tainted 4.15.0-rc5+ #237
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
> Google 01/01/2011
> Call Trace:
>  <#DB>
>  __dump_stack lib/dump_stack.c:17 [inline]
>  dump_stack+0x194/0x257 lib/dump_stack.c:53
>  panic+0x1e4/0x41c kernel/panic.c:183
>  __warn+0x1dc/0x200 kernel/panic.c:547
>  report_bug+0x211/0x2d0 lib/bug.c:184
>  fixup_bug.part.11+0x37/0x80 arch/x86/kernel/traps.c:178
>  fixup_bug arch/x86/kernel/traps.c:247 [inline]
>  do_error_trap+0x2d7/0x3e0 arch/x86/kernel/traps.c:296
>  do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:315
>  invalid_op+0x22/0x40 arch/x86/entry/entry_64.S:1061
> RIP: 0010:cond_local_irq_disable arch/x86/kernel/traps.c:86 [inline]
> RIP: 0010:do_debug+0x4d8/0x6e0 arch/x86/kernel/traps.c:815
> RSP: 0018:fffffe800000ee98 EFLAGS: 00010246
> RAX: dffffc0000000000 RBX: fffffe800000ef58 RCX: 0000000000000000
> RDX: 1fffffd000001dfc RSI: 0000000000000001 RDI: ffffffff85ec81f8
> RBP: fffffe800000ef48 R08: fffffe800000efe8 R09: 0000000000000000
> R10: 0000000000000000 R11: 0000000000000000 R12: 000000000000e003
> R13: ffff8801c2340040 R14: 1fffffd000001dd8 R15: 0000000000004000
>  debug+0x34/0x60 arch/x86/entry/entry_64.S:1214
> RIP: 0010:__put_user_8+0x1f/0x25 arch/x86/lib/putuser.S:83
> RSP: 0018:ffff8801c9f8ff28 EFLAGS: 00000293
> RAX: 000000005a4195b6 RBX: 00007fffffffeff9 RCX: 0000000020000000
> RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000282
> RBP: ffff8801c9f8ff48 R08: 0000000000000000 R09: 1ffff100393f1fc2
> R10: ffff8801c9f8fdd8 R11: 0000000000000000 R12: 000000005a4195b6
> R13: 0000000020000000 R14: 00007f2c937f99c0 R15: 0000000000000001
>  </#DB>
>  entry_SYSCALL_64_fastpath+0x1f/0x96
> RIP: 0033:0x44aef9
> RSP: 002b:00007f2c937f8ce8 EFLAGS: 00000206 ORIG_RAX: 00000000000000c9
> RAX: ffffffffffffffda RBX: 00000000006dcc24 RCX: 000000000044aef9
> RDX: 000000000044aef9 RSI: 000000000044aef9 RDI: 0000000020000000
> RBP: 00000000006dcc20 R08: 0000000000000000 R09: 0000000000000000
> R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
> R13: 00007ffe9191073f R14: 00007f2c937f99c0 R15: 0000000000000001
>
> Dumping ftrace buffer:
>    (ftrace buffer empty)
> Kernel Offset: disabled
> Rebooting in 86400 seconds..
>