syzbot


WARNING in __kvm_gpc_refresh (3)

Status: upstream: reported C repro on 2025/01/02 09:06
Subsystems: kvm
[Documentation on labels]
Reported-by: syzbot+cde12433b6c56f55d9ed@syzkaller.appspotmail.com
First crash: 210d, last: 17d
Cause bisection: failed (error log, bisect log)
  
Discussions (3)
Title Replies (including bot) Last reply
[syzbot] Monthly kvm report (May 2025) 0 (1) 2025/05/12 13:34
[syzbot] [kvm?] WARNING in __kvm_gpc_refresh (3) 0 (2) 2025/02/26 17:36
[syzbot] Monthly kvm report (Jan 2025) 0 (1) 2025/01/13 10:54
Similar bugs (2)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream WARNING in __kvm_gpc_refresh kvm -1 C 178 431d 496d 25/29 fixed on 2024/05/22 23:08
upstream WARNING in __kvm_gpc_refresh (2) kvm -1 C error 2 411d 425d 27/29 fixed on 2024/08/14 03:44
Last patch testing requests (4)
Created Duration User Patch Repo Result
2025/07/24 22:37 24m retest repro linux-next error
2025/07/10 17:28 42m retest repro upstream report log
2025/05/23 13:30 17m retest repro linux-next report log
2025/03/12 17:51 23m retest repro linux-next error

Sample crash report:
------------[ cut here ]------------
WARNING: CPU: 2 PID: 5927 at arch/x86/kvm/../../../virt/kvm/pfncache.c:267 __kvm_gpc_refresh+0x13c3/0x1b60 virt/kvm/pfncache.c:267
Modules linked in:
CPU: 2 UID: 0 PID: 5927 Comm: syz-executor147 Not tainted 6.16.0-rc3-syzkaller-00044-g7595b66ae9de #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:__kvm_gpc_refresh+0x13c3/0x1b60 virt/kvm/pfncache.c:267
Code: c1 ea 03 80 3c 02 00 0f 85 a2 06 00 00 48 89 9d 08 01 00 00 48 8b 3c 24 31 db e8 48 07 4a 0a e9 13 fa ff ff e8 3e f7 82 00 90 <0f> 0b 90 e9 a0 fb ff ff e8 30 f7 82 00 4c 89 f2 48 b8 00 00 00 00
RSP: 0018:ffffc900031e7290 EFLAGS: 00010293
RAX: 0000000000000000 RBX: ffffffffffffffff RCX: ffffffff81391376
RDX: ffff888022d88000 RSI: ffffffff81392662 RDI: 0000000000000000
RBP: ffffc90003c1e3c0 R08: 0000000000000000 R09: 0000000000000001
R10: 0000000000000001 R11: 0000000000000001 R12: ffff888000000000
R13: ffffc90003c1e401 R14: ffff888000000001 R15: ffffc900031e74a0
FS:  00005555722c7380(0000) GS:ffff8880d6952000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055ab4eb98168 CR3: 0000000029030000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 kvm_gpc_refresh+0xec/0x170 virt/kvm/pfncache.c:382
 kvm_xen_set_evtchn.part.0+0x19c/0x270 arch/x86/kvm/xen.c:1943
 kvm_xen_set_evtchn arch/x86/kvm/xen.c:2033 [inline]
 kvm_xen_hvm_evtchn_send+0x22f/0x290 arch/x86/kvm/xen.c:2023
 kvm_arch_vm_ioctl+0x112e/0x1cf0 arch/x86/kvm/x86.c:7315
 kvm_vm_ioctl+0x19bb/0x3da0 virt/kvm/kvm_main.c:5360
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:907 [inline]
 __se_sys_ioctl fs/ioctl.c:893 [inline]
 __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:893
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7efd370b1369
Code: 48 83 c4 28 c3 e8 37 17 00 00 0f 1f 80 00 00 00 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fff6557a5d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fff6557a7a8 RCX: 00007efd370b1369
RDX: 0000200000000400 RSI: 00000000400caed0 RDI: 0000000000000005
RBP: 00007efd37124610 R08: 00007fff6557a7a8 R09: 00007fff6557a7a8
R10: 00007fff6557a7a8 R11: 0000000000000246 R12: 0000000000000001
R13: 00007fff6557a798 R14: 0000000000000001 R15: 0000000000000001
 </TASK>

Crashes (11):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/06/25 15:49 upstream 7595b66ae9de 26d77996 .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in __kvm_gpc_refresh
2025/06/26 17:13 linux-next ecb259c4f70d 26d77996 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce WARNING in __kvm_gpc_refresh
2025/02/26 17:35 linux-next e5d3fd687aac d34966d1 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in __kvm_gpc_refresh
2025/05/08 06:13 upstream 707df3375124 dbf35fa1 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2025/06/25 15:40 upstream 7595b66ae9de 26d77996 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in __kvm_gpc_refresh
2025/06/25 15:39 upstream 7595b66ae9de 26d77996 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in __kvm_gpc_refresh
2025/05/09 05:15 upstream 2c89c1b655c0 bb813bcc .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in __kvm_gpc_refresh
2025/01/24 08:44 upstream 8883957b3c9d 521b0ce3 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in __kvm_gpc_refresh
2024/12/29 08:58 upstream 059dd502b263 d3ccff63 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in __kvm_gpc_refresh
2025/06/06 03:46 linux-next 4f27f06ec121 6b6b5f21 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in __kvm_gpc_refresh
2025/02/26 16:08 linux-next e5d3fd687aac d34966d1 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in __kvm_gpc_refresh
* Struck through repros no longer work on HEAD.