syzbot


WARNING in vcpu_run

Status: upstream: reported C repro on 2024/10/25 16:30
Subsystems: kvm-x86
[Documentation on labels]
Reported-by: syzbot+1522459a74d26b0ac33a@syzkaller.appspotmail.com
First crash: 307d, last: 2d06h
Cause bisection: introduced by (bisect log) :
commit 45405155d876c326da89162b8173b8cc9ab7ed75
Author: Sean Christopherson <seanjc@google.com>
Date: Fri Jun 7 17:26:09 2024 +0000

  KVM: x86: WARN if a vCPU gets a valid wakeup that KVM can't yet inject

Crash: WARNING in kvm_arch_vcpu_ioctl_run (log)
Repro: C syz .config
  
Discussions (7)
Title Replies (including bot) Last reply
[syzbot] Monthly kvm-x86 report (Jun 2025) 0 (1) 2025/06/08 17:33
[syzbot] Monthly kvm report (May 2025) 0 (1) 2025/05/12 13:34
[syzbot] Monthly kvm report (Apr 2025) 0 (1) 2025/04/02 09:38
[syzbot] Monthly kvm report (Feb 2025) 0 (1) 2025/02/11 13:32
[syzbot] Monthly kvm report (Dec 2024) 0 (1) 2024/12/11 11:27
[syzbot] [kvm?] WARNING in vcpu_run 0 (2) 2024/12/10 09:38
[syzbot] Monthly kvm report (Nov 2024) 0 (1) 2024/11/01 12:35
Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-6-12 WARNING in vcpu_run origin:upstream -1 C 4 22h53m 23h54m 0/1 premoderation: reported C repro on 2025/08/27 20:44
Last patch testing requests (6)
Created Duration User Patch Repo Result
2025/06/06 23:24 19m retest repro upstream report log
2025/03/28 21:46 24m retest repro upstream error
2025/01/31 19:26 15m retest repro upstream report log
2025/01/17 13:11 3h16m retest repro upstream report log
2024/11/08 12:39 29m retest repro upstream report log
2024/11/08 12:39 21m retest repro upstream report log
Fix bisection attempts (5)
Created Duration User Patch Repo Result
2025/08/14 09:55 3h00m bisect fix upstream OK (0) job log log
2025/07/12 14:50 4h31m bisect fix upstream OK (0) job log log
2025/05/12 03:58 3h01m bisect fix upstream OK (0) job log log
2025/04/01 22:42 2h48m bisect fix upstream OK (0) job log log
2025/03/02 19:43 2h24m bisect fix upstream OK (0) job log log
Cause bisection attempts (2)
Created Duration User Patch Repo Result
2024/12/10 02:06 7h30m bisect upstream OK (1) job log log
2024/10/25 21:47 4h33m bisect upstream OK (1) job log log
marked invalid by nogikh@google.com

Sample crash report:
------------[ cut here ]------------
WARNING: CPU: 0 PID: 6063 at arch/x86/kvm/x86.c:11179 vcpu_block arch/x86/kvm/x86.c:11179 [inline]
WARNING: CPU: 0 PID: 6063 at arch/x86/kvm/x86.c:11179 vcpu_run+0x6d6d/0x6fa0 arch/x86/kvm/x86.c:11221
Modules linked in:
CPU: 0 UID: 0 PID: 6063 Comm: syz.0.18 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:vcpu_block arch/x86/kvm/x86.c:11179 [inline]
RIP: 0010:vcpu_run+0x6d6d/0x6fa0 arch/x86/kvm/x86.c:11221
Code: 48 83 c3 20 48 89 d8 48 c1 e8 03 42 0f b6 04 38 84 c0 0f 85 16 02 00 00 44 88 33 eb 10 e8 4b b9 78 00 eb 09 e8 44 b9 78 00 90 <0f> 0b 90 45 31 ed 48 c7 84 24 c0 02 00 00 0e 36 e0 45 48 8b 84 24
RSP: 0018:ffffc90003027600 EFLAGS: 00010293
RAX: ffffffff8146f24c RBX: 00000000fffffff0 RCX: ffff8880266d8000
RDX: 0000000000000000 RSI: 00000000fffffff0 RDI: 00000000fffffff0
RBP: ffffc900030279d0 R08: ffff888075ba8ee7 R09: 1ffff1100eb751dc
R10: dffffc0000000000 R11: ffffed100eb751dd R12: ffff888031a32a18
R13: ffff888031a32940 R14: ffff888031a32978 R15: dffffc0000000000
FS:  00007f4f38bdd6c0(0000) GS:ffff888125c1b000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4f38bdcf98 CR3: 0000000073094000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 kvm_arch_vcpu_ioctl_run+0xfc9/0x1940 arch/x86/kvm/x86.c:11564
 kvm_vcpu_ioctl+0x95c/0xe90 virt/kvm/kvm_main.c:4466
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:598 [inline]
 __se_sys_ioctl+0xf9/0x170 fs/ioctl.c:584
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4f3958ebe9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f4f38bdd038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f4f397b6270 RCX: 00007f4f3958ebe9
RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000005
RBP: 00007f4f39611e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4f397b6308 R14: 00007f4f397b6270 R15: 00007fff03497a78
 </TASK>

Crashes (7):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/08/26 13:56 upstream fab1beda7597 bf27483f .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in vcpu_run
2024/10/25 08:56 upstream ae90f6a6170d c79b8ca5 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in vcpu_run
2024/10/25 08:20 upstream ae90f6a6170d c79b8ca5 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in vcpu_run
2024/12/10 19:50 upstream 7cb1b4663150 cfc402b4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in vcpu_run
2024/10/25 07:40 upstream ae90f6a6170d c79b8ca5 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in vcpu_run
2024/12/19 05:32 upstream c061cf420ded 1432fc84 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in vcpu_run
2024/12/16 19:16 upstream 78d4f34e2115 eec85da6 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in vcpu_run
* Struck through repros no longer work on HEAD.