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: 651d, last: 56m
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 872d 937d 25/29 fixed on 2024/05/22 23:08
upstream WARNING in __kvm_gpc_refresh (2) kvm -1 syz, C error 2 852d 866d 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+0x1510/0x1710 virt/kvm/pfncache.c:267, CPU#0: syz-executor382/5629
Modules linked in:
CPU: 0 UID: 0 PID: 5629 Comm: syz-executor382 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
RIP: 0010:__kvm_gpc_refresh+0x1510/0x1710 virt/kvm/pfncache.c:267
Code: c6 05 3b fd 22 10 01 48 c7 c7 6a f9 44 8e be 43 04 00 00 48 c7 c2 00 44 02 8c e8 cb de 62 00 e9 81 ee ff ff e8 41 3b 87 00 90 <0f> 0b 90 bb ea ff ff ff 49 bf 00 00 00 00 00 fc ff df e9 4b f6 ff
RSP: 0018:ffffc90003b9f1c0 EFLAGS: 00010293
RAX: ffffffff8140d4cf RBX: ffff888000000000 RCX: ffff88807d7c8000
RDX: 0000000000000000 RSI: ffff888000000000 RDI: ffff888000000000
RBP: ffffc90003b9f350 R08: ffffffff917a727f R09: 1ffffffff22f4e4f
R10: dffffc0000000000 R11: fffffbfff22f4e50 R12: 1ffff92000773e4c
R13: ffff8880294a9b60 R14: ffff888000000000 R15: ffffffffffffff01
FS:  0000555568d86400(0000) GS:ffff888123abf000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005575e03b2000 CR3: 00000000331e4000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 kvm_gpc_refresh+0xe1/0x110 virt/kvm/pfncache.c:382
 kvm_xen_set_evtchn+0x14f/0x220 arch/x86/kvm/xen.c:1966
 kvm_xen_hvm_evtchn_send+0x120/0x1e0 arch/x86/kvm/xen.c:2057
 kvm_arch_vm_ioctl+0xfad/0x1a10 arch/x86/kvm/x86.c:4639
 kvm_vm_ioctl+0x8f7/0xd30 virt/kvm/kvm_main.c:5410
 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:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa251324e79
Code: c0 79 93 eb d5 48 8d 7c 1d 00 eb 99 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 d8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fffb8bfdac8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fffb8bfdbf8 RCX: 00007fa251324e79
RDX: 0000200000000980 RSI: 00000000400caed0 RDI: 0000000000000004
RBP: 0000000000000001 R08: 00007fffb8bfdbf8 R09: 00007fffb8bfdbf8
R10: 00007fffb8bfdbf8 R11: 0000000000000246 R12: 00007fffb8bfdbe8
R13: 0000000000000002 R14: 00007fa2513b5ca0 R15: 0000000000000002
 </TASK>

Crashes (2112):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/10/10 18:18 upstream 3857c2fe5449 4f92358f .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
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
2026/10/11 15:53 upstream a5ebb76233b7 4f92358f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/10/11 13:37 upstream a5ebb76233b7 4f92358f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/10/11 06:01 upstream a5ebb76233b7 4f92358f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/10/11 00:21 upstream 3857c2fe5449 4f92358f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/10/10 21:37 upstream 3857c2fe5449 4f92358f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/10/10 13:26 upstream 3857c2fe5449 4f92358f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/10/10 11:59 upstream 3857c2fe5449 4f92358f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/10/10 10:08 upstream 3857c2fe5449 4f92358f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/10/10 03:53 upstream af32da41b032 a8add9cd .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/10/10 00:40 upstream af32da41b032 a8add9cd .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/10/09 10:00 upstream 6c377d19d4a5 b2734a59 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/10/09 08:44 upstream 6c377d19d4a5 b2734a59 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/10/08 18:20 upstream 7b63ef2d55f2 4f6a9fcf .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/10/08 16:13 upstream 7b63ef2d55f2 4f6a9fcf .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/10/08 16:13 upstream 7b63ef2d55f2 4f6a9fcf .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/10/07 23:12 upstream 602042bf29f6 6520ecdb .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/10/07 17:00 upstream 602042bf29f6 6520ecdb .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/10/07 15:39 upstream 602042bf29f6 6520ecdb .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/10/07 07:18 upstream 69f80fef3153 f7710056 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/10/07 05:32 upstream 69f80fef3153 f7710056 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/10/05 22:46 upstream 67f0943b394d 1995e6c7 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/10/05 19:06 upstream 67f0943b394d 1995e6c7 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/10/05 16:00 upstream a90ee4305c4a 1995e6c7 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/10/05 08:17 upstream a90ee4305c4a 57bbd979 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/10/05 01:13 upstream 6addb4f38557 57bbd979 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/10/04 23:53 upstream 6addb4f38557 57bbd979 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/10/04 22:50 upstream 6addb4f38557 57bbd979 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/10/04 17:39 upstream 6addb4f38557 57bbd979 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/10/04 06:42 upstream a74306e2e676 57bbd979 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/10/04 04:56 upstream a74306e2e676 57bbd979 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/10/04 02:41 upstream a74306e2e676 57bbd979 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/10/03 15:42 upstream e767a4ea70a3 57bbd979 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/10/03 07:48 upstream ce1e0223d8ad 57bbd979 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/10/02 18:22 upstream ce1e0223d8ad 57bbd979 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/10/02 04:08 upstream d24e8ac715de 6d32eb1f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/10/02 01:18 upstream d24e8ac715de 6d32eb1f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/10/02 00:29 upstream d24e8ac715de 6d32eb1f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/10/01 11:52 upstream 551c722f4080 38f7f0d1 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/10/01 10:29 upstream 551c722f4080 38f7f0d1 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/10/01 09:12 upstream 551c722f4080 38f7f0d1 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/10/01 06:05 upstream 551c722f4080 38f7f0d1 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in __kvm_gpc_refresh
2026/10/01 03:05 upstream 551c722f4080 892a21ec .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
2026/10/05 07:09 upstream a90ee4305c4a 57bbd979 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 WARNING in __kvm_gpc_refresh
2026/10/03 22:14 upstream e767a4ea70a3 57bbd979 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 WARNING in __kvm_gpc_refresh
2026/10/03 20:48 upstream e767a4ea70a3 57bbd979 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 WARNING in __kvm_gpc_refresh
2026/10/03 01:16 upstream ce1e0223d8ad 57bbd979 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 WARNING in __kvm_gpc_refresh
2026/10/02 11:25 upstream d24e8ac715de 6d32eb1f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 WARNING in __kvm_gpc_refresh
2026/10/01 01:40 upstream 551c722f4080 892a21ec .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 WARNING in __kvm_gpc_refresh
2026/10/05 04:56 upstream a90ee4305c4a 57bbd979 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in __kvm_gpc_refresh
2026/10/05 04:50 upstream a90ee4305c4a 57bbd979 .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
2026/09/27 02:16 linux-next f5f84daefcd9 a3c7249d .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.