WARNING in __kvm_gpc_refresh (3)

Status: upstream: reported C repro on 2025/01/02 09:06
Subsystems: kvm
Labels: prio:high
[Documentation on labels]
Reported-by: syzbot+cde12433b6c56f55d9ed@syzkaller.appspotmail.com
First crash: 628d, last: 4h06m
Cause bisection: failed (error log, bisect log)
  
▶ ▼ ✨ AI Patch Versions (2)
Version Stage Reported Report Link Job
2 moderation 2026/07/29 14:55 Discussion 06c5ed03-3710-4a03-8db9-c370eb80da49
1 moderation 2026/07/29 13:17 Discussion 4e819403-979c-4f19-96ab-28961c06eab0
▶ ▼ ✨ AI Jobs (4)
ID Workflow Result Correct Bug Created Started Finished Revision
abbf13cf patch-iteration ❓ WARNING in __kvm_gpc_refresh (3) 2026/08/06 12:10 2026/08/06 12:10 2026/08/06 12:35 cd5b1963
06c5ed03 patch-iteration ❓ WARNING in __kvm_gpc_refresh (3) 2026/07/29 14:11 2026/07/29 14:11 2026/07/29 14:55 74755bb6
4e819403 patching ❓ WARNING in __kvm_gpc_refresh (3) 2026/07/29 09:27 2026/07/29 10:45 2026/07/29 13:17 19622d9d
ecaaf59e assessment-security DenialOfService: ❌ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ✅ UserNamespace: ✅ VMGuestTrigger: ✅ VMHostTrigger: ❌ ❓ WARNING in __kvm_gpc_refresh (3) 2026/05/21 17:13 2026/05/21 17:13 2026/05/21 18:07 d5742584
▶ ▼ Discussions (16)
Title Replies (including bot) Last reply
[syzbot] Monthly kvm report (Sep 2026) 0 (1) 2026/09/16 12:33
[syzbot] Monthly kvm report (Aug 2026) 0 (1) 2026/08/16 12:32
[syzbot] Monthly kvm report (Jul 2026) 0 (1) 2026/07/16 04:32
[syzbot] Monthly kvm report (Jun 2026) 0 (1) 2026/06/07 20:32
[syzbot] Monthly kvm report (May 2026) 0 (1) 2026/05/07 20:32
[syzbot] Monthly kvm report (Mar 2026) 0 (1) 2026/03/27 20:35
[PATCH] KVM: pfncache: Fix uhva validity check in kvm_gpc_is_valid_len() 4 (4) 2026/03/09 19:39
[syzbot] [kvm?] WARNING in __kvm_gpc_refresh (3) 0 (4) 2026/03/09 05:15
[syzbot] Monthly kvm report (Feb 2026) 0 (1) 2026/02/16 12:34
[syzbot] Monthly kvm report (Jan 2026) 0 (1) 2026/01/12 08:40
[syzbot] Monthly kvm report (Dec 2025) 0 (1) 2025/12/11 05:58
[syzbot] Monthly kvm report (Nov 2025) 0 (1) 2025/11/10 09:15
[syzbot] Monthly kvm report (Oct 2025) 0 (1) 2025/10/10 07:32
[syzbot] Monthly kvm report (Sep 2025) 0 (1) 2025/09/01 07:38
[syzbot] Monthly kvm report (May 2025) 0 (1) 2025/05/12 13:34
[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 syz, C 178 850d 914d 25/29 fixed on 2024/05/22 23:08
upstream WARNING in __kvm_gpc_refresh (2) kvm -1 syz, C error 2 829d 843d 27/29 fixed on 2024/08/14 03:44
▶ ▼ Last patch testing requests (12)
Created Duration User Patch Repo Result
2026/03/29 23:35 19m retest repro linux-next report log
2026/03/09 05:15 17m phind.uet@gmail.com patch linux-next OK log
2026/03/09 04:25 12m phind.uet@gmail.com linux-next report log
2026/02/27 10:22 13m retest repro upstream report log
2026/02/04 23:09 56m retest repro linux-next report log
2026/02/04 23:09 58m retest repro linux-next report log
2026/02/04 23:26 13m retest repro upstream report log
2026/02/04 23:04 16m retest repro upstream log
2025/10/16 08:13 19m retest repro linux-next report log
2025/10/16 08:13 20m retest repro linux-next report log
2025/10/02 04:33 14m retest repro upstream report log
2025/08/02 09:16 8m retest repro linux-next error

Sample crash report:
kvm_intel: L1TF CPU bug present and SMT on, data leak possible. See CVE-2018-3646 and https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/l1tf.html for details.
------------[ cut here ]------------
kvm_is_error_gpa(gpa) == kvm_is_error_hva(uhva)
WARNING: arch/x86/kvm/../../../virt/kvm/pfncache.c:267 at __kvm_gpc_refresh+0x1219/0x13a0 virt/kvm/pfncache.c:267, CPU#0: syz.0.17/6008
Modules linked in:
CPU: 0 UID: 0 PID: 6008 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
RIP: 0010:__kvm_gpc_refresh+0x1219/0x13a0 virt/kvm/pfncache.c:267
Code: c6 05 72 ab ba 0e 01 48 c7 c7 18 36 ee 8d be 34 04 00 00 48 c7 c2 00 3d c2 8b e8 62 e0 60 00 e9 6a f1 ff ff e8 18 bf 84 00 90 <0f> 0b 90 bb ea ff ff ff e9 a4 f8 ff ff e8 05 bf 84 00 90 0f 0b 90
RSP: 0018:ffffc90002f271c0 EFLAGS: 00010293
RAX: ffffffff814100d8 RBX: ffff888000000000 RCX: ffff888035479e80
RDX: 0000000000000000 RSI: ffff888000000000 RDI: ffff888000000000
RBP: ffffc90002f27348 R08: ffffffff9011dab7 R09: 1ffffffff2023b56
R10: dffffc0000000000 R11: fffffbfff2023b57 R12: ffff888078391290
R13: dffffc0000000000 R14: ffff888000000000 R15: ffffffffffffff01
FS:  000055556a986500(0000) GS:ffff888125454000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000000 CR3: 0000000036cb6000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 kvm_gpc_refresh+0xe1/0x140 virt/kvm/pfncache.c:382
 kvm_xen_set_evtchn+0x163/0x230 arch/x86/kvm/xen.c:1942
 kvm_xen_hvm_evtchn_send+0x120/0x1e0 arch/x86/kvm/xen.c:2033
 kvm_arch_vm_ioctl+0xfb1/0x1a10 arch/x86/kvm/x86.c:7518
 kvm_vm_ioctl+0x905/0xd50 virt/kvm/kvm_main.c:5387
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f92ca59c819
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fff43137188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f92ca815fa0 RCX: 00007f92ca59c819
RDX: 0000200000000400 RSI: 00000000400caed0 RDI: 0000000000000005
RBP: 00007f92ca632c91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f92ca815fac R14: 00007f92ca815fa0 R15: 00007f92ca815fa0
 </TASK>

Crashes (1899):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/04/10 11:59 upstream 9a9c8ce300cd 38c8e246 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/07/22 09:01 upstream 248951ddc14d b561ce9c .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in __kvm_gpc_refresh
2026/02/05 04:15 upstream f14faaf3a1fb ea10c935 .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in __kvm_gpc_refresh
2025/10/26 23:54 upstream dbfc6422a34d c0460fcd .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in __kvm_gpc_refresh
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
2026/07/22 10:24 linux-next cc2b5f627e8c b561ce9c .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce WARNING in __kvm_gpc_refresh
2026/02/13 09:41 linux-next af98e93c5c39 6a673c50 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in __kvm_gpc_refresh
2026/02/05 04:52 linux-next 0f8a890c4524 ea10c935 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce WARNING in __kvm_gpc_refresh
2025/10/27 03:31 linux-next 72fb0170ef1f c0460fcd .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce 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
2026/09/19 00:47 upstream f259f446f519 8d7d05f1 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/09/18 22:11 upstream f259f446f519 8d7d05f1 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/09/18 18:20 upstream 5dd1818b15d9 8d7d05f1 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/09/18 16:38 upstream 5dd1818b15d9 8d7d05f1 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/09/18 15:17 upstream 5dd1818b15d9 8d7d05f1 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/09/18 14:11 upstream 5dd1818b15d9 8d7d05f1 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/09/18 00:41 upstream 4982d3552a3b 95928915 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/09/17 21:00 upstream 4982d3552a3b 95928915 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/09/17 20:18 upstream 4982d3552a3b 95928915 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/09/17 16:49 upstream 238650ef6c7c 95928915 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/09/17 15:23 upstream 238650ef6c7c 95928915 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/09/17 10:23 upstream 238650ef6c7c 95928915 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/09/17 08:42 upstream 238650ef6c7c 95928915 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/09/17 02:54 upstream 9b87fdc9af2f 95928915 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/09/16 23:57 upstream 9b87fdc9af2f 95928915 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/09/16 21:05 upstream 9b87fdc9af2f 95928915 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/09/16 19:26 upstream 9b87fdc9af2f 95928915 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/09/16 18:49 upstream 9b87fdc9af2f 95928915 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/09/16 17:39 upstream 9b87fdc9af2f 95928915 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/09/16 12:32 upstream 9b87fdc9af2f 12a0a44a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/09/16 02:44 upstream 9b87fdc9af2f 12a0a44a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/09/15 23:03 upstream 587858367581 81a27d1a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/09/15 20:55 upstream 587858367581 81a27d1a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/09/15 19:32 upstream 587858367581 81a27d1a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/09/15 18:08 upstream 587858367581 81a27d1a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/09/15 16:41 upstream 587858367581 81a27d1a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/09/15 15:23 upstream 587858367581 81a27d1a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/09/15 13:58 upstream 587858367581 81a27d1a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/09/15 12:25 upstream 587858367581 81a27d1a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/09/15 08:55 upstream 587858367581 81a27d1a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/09/15 03:37 upstream 587858367581 924033e8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/09/14 20:52 upstream 704340f1cd0d 924033e8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/09/14 16:55 upstream 704340f1cd0d 924033e8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/09/14 14:42 upstream 704340f1cd0d 924033e8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/09/14 08:42 upstream 704340f1cd0d 70a60e12 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/09/14 04:01 upstream 2f0c1cf72f46 70a60e12 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/09/14 01:47 upstream 2f0c1cf72f46 70a60e12 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/09/13 19:32 upstream 2f0c1cf72f46 70a60e12 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/09/13 12:08 upstream cba2348ab114 70a60e12 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/09/13 11:11 upstream cba2348ab114 70a60e12 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/09/13 09:57 upstream cba2348ab114 70a60e12 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/09/13 08:54 upstream cba2348ab114 70a60e12 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/09/13 02:49 upstream cba2348ab114 70a60e12 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/09/12 21:58 upstream 5225b8eec4c9 70a60e12 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/09/12 17:47 upstream 5225b8eec4c9 70a60e12 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/09/12 15:45 upstream 5225b8eec4c9 70a60e12 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/08/05 17:18 upstream c21bb4193868 b3eac40e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root WARNING in __kvm_gpc_refresh
2026/07/31 08:07 upstream 3708dd948844 aaffb173 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in __kvm_gpc_refresh
2026/09/15 04:41 upstream 50d05c7c76c9 924033e8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 WARNING in __kvm_gpc_refresh
2026/09/14 09:42 upstream 50d05c7c76c9 70a60e12 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 WARNING in __kvm_gpc_refresh
2026/09/13 00:10 upstream 50d05c7c76c9 70a60e12 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 WARNING in __kvm_gpc_refresh
2026/09/14 19:05 upstream 704340f1cd0d 924033e8 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in __kvm_gpc_refresh
2026/09/13 23:02 upstream d681d7ef617e 70a60e12 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in __kvm_gpc_refresh
2026/09/07 21:04 upstream df2908090cda 5e4626f5 .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
2026/08/03 06:40 upstream bd1dde877520 e611ffe1 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in __kvm_gpc_refresh
2026/08/09 03:51 linux-next cc2b5f627e8c 5d63f80b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce WARNING in __kvm_gpc_refresh
* Struck through repros no longer work on HEAD.