syzbot


WARNING in kvm_read_guest_offset_cached

Status: upstream: reported C repro on 2025/07/16 05:05
Subsystems: kvm
[Documentation on labels]
Reported-by: syzbot+bc0e18379a290e5edfe4@syzkaller.appspotmail.com
First crash: 5d08h, last: 3d11h
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [kvm?] WARNING in kvm_read_guest_offset_cached 1 (2) 2025/07/16 15:23
Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-6-12 WARNING in kvm_read_guest_offset_cached origin:upstream -1 C 1 5d06h 5d06h 0/1 premoderation: reported C repro on 2025/07/16 05:33

Sample crash report:
------------[ cut here ]------------
WARNING: CPU: 0 PID: 6107 at arch/x86/kvm/../../../virt/kvm/kvm_main.c:3459 kvm_read_guest_offset_cached+0x3f5/0x4b0 virt/kvm/kvm_main.c:3459
Modules linked in:
CPU: 0 UID: 0 PID: 6107 Comm: syz.0.16 Not tainted 6.16.0-rc6-syzkaller-00002-g155a3c003e55 #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_read_guest_offset_cached+0x3f5/0x4b0 virt/kvm/kvm_main.c:3459
Code: 0f 01 e8 3e 6c 61 00 e9 9b fc ff ff e8 14 25 85 00 48 8b 3c 24 31 d2 48 89 ee e8 16 bf fa 00 e9 2e fe ff ff e8 fc 24 85 00 90 <0f> 0b 90 bb ea ff ff ff e9 4d fe ff ff e8 e9 24 85 00 48 8b 74 24
RSP: 0018:ffffc9000349f960 EFLAGS: 00010293
RAX: 0000000000000000 RBX: ffff888050329898 RCX: ffffffff8136ca66
RDX: ffff88803cfa8000 RSI: ffffffff8136cd84 RDI: 0000000000000006
RBP: 0000000000000004 R08: 0000000000000006 R09: 0000000000000008
R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000004
R13: ffffc90003921000 R14: 0000000000000000 R15: ffffc900039215a0
FS:  000055558378f500(0000) GS:ffff8880d6713000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000025de6000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 apf_pageready_slot_free arch/x86/kvm/x86.c:13452 [inline]
 kvm_arch_can_dequeue_async_page_present+0x172/0x310 arch/x86/kvm/x86.c:13571
 kvm_check_async_pf_completion+0x61/0x440 virt/kvm/async_pf.c:158
 vcpu_enter_guest arch/x86/kvm/x86.c:10930 [inline]
 vcpu_run+0x48c2/0x5500 arch/x86/kvm/x86.c:11335
 kvm_arch_vcpu_ioctl_run+0x51e/0x18c0 arch/x86/kvm/x86.c:11658
 kvm_vcpu_ioctl+0x5eb/0x1690 virt/kvm/kvm_main.c:4464
 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: 0033:0x7fdb7658e929
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:00007ffd25fe7d98 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fdb767b5fa0 RCX: 00007fdb7658e929
RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000005
RBP: 00007fdb76610b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fdb767b5fa0 R14: 00007fdb767b5fa0 R15: 0000000000000003
 </TASK>

Crashes (4):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/07/16 04:24 upstream 155a3c003e55 03fcfc4b .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in kvm_read_guest_offset_cached
2025/07/16 04:05 upstream 155a3c003e55 03fcfc4b .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in kvm_read_guest_offset_cached
2025/07/18 00:33 linux-next 024e09e444bd 0d1223f1 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce WARNING in kvm_read_guest_offset_cached
2025/07/16 03:45 upstream 155a3c003e55 03fcfc4b .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in kvm_read_guest_offset_cached
* Struck through repros no longer work on HEAD.