WARNING in virtio_gpu_alloc_vbufs

Status: upstream: reported on 2026/07/30 00:09
Subsystems: virt dri
Labels: prio:high
[Documentation on labels]
Reported-by: syzbot+1b129b44597a126d2d79@syzkaller.appspotmail.com
First crash: 5d05h, last: now
✨ AI Jobs (2)
ID Workflow Result Correct Bug Created Started Finished Revision Error
c3c8b670 repro 💥 WARNING in virtio_gpu_alloc_vbufs 2026/07/30 09:10 2026/07/30 09:10 2026/07/30 10:12 2377cd3d
tool reproduce-crash failed: error: failed to collect 3 valid runs within 6 total attempts. Last infra error: failed to read coverage file /tmp/syz-cover-1785406043906720739_prog1.0 in VM: failed to r...
truncated to first 200 bytes; open job for full error
999160bc assessment-security DenialOfService: ❌ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ✅ VMHostTrigger: ✅ WARNING in virtio_gpu_alloc_vbufs 2026/07/27 00:48 2026/07/27 00:48 2026/07/27 01:37 492bab15

			
		
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [virt?] [dri?] WARNING in virtio_gpu_alloc_vbufs 0 (1) 2026/07/30 00:09

Sample crash report:
[drm] features: -virgl +edid -resource_blob -host_visible
[drm] features: -context_init -blob_alignment
------------[ cut here ]------------
kmem_cache of name 'virtio-gpu-vbufs' already exists
WARNING: mm/slab_common.c:111 at kmem_cache_sanity_check mm/slab_common.c:111 [inline], CPU#3: syz.8.3231/17254
WARNING: mm/slab_common.c:111 at __kmem_cache_create_args+0xa6/0x420 mm/slab_common.c:352, CPU#3: syz.8.3231/17254
Modules linked in:
CPU: 3 UID: 0 PID: 17254 Comm: syz.8.3231 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:kmem_cache_sanity_check mm/slab_common.c:111 [inline]
RIP: 0010:__kmem_cache_create_args+0xa9/0x420 mm/slab_common.c:352
Code: 48 8b 43 60 48 8d 58 a0 48 3d 30 82 d8 8e 74 1f 48 8b 7b 58 48 89 ee e8 a5 a3 5d 09 85 c0 75 e0 48 8d 3d fa 2d ce 0e 48 89 ee <67> 48 0f b9 3a be 20 00 00 00 48 89 ef e8 25 a5 5d 09 48 85 c0 0f
RSP: 0018:ffffc900035aef58 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff888102a9d680 RCX: fffff520006b5dc6
RDX: 0000000000000000 RSI: ffffffff8c6f8ae0 RDI: ffffffff912750c0
RBP: ffffffff8c6f8ae0 R08: 0000000000000000 R09: fffffbfff2244f3a
R10: ffffc900035aef58 R11: 0000000000000000 R12: 0000000000000000
R13: ffffc900035aefc8 R14: 00000000000000d8 R15: 0000000000000000
FS:  00007fdf9365b6c0(0000) GS:ffff8880d60dc000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f92cca88ff8 CR3: 000000003a84a000 CR4: 0000000000352ef0
DR0: 0000000000000005 DR1: 0000000000000005 DR2: 0000000020040004
DR3: 0000000000000056 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 __kmem_cache_create include/linux/slab.h:399 [inline]
 virtio_gpu_alloc_vbufs+0xc2/0x150 drivers/gpu/drm/virtio/virtgpu_vq.c:75
 virtio_gpu_init.cold+0x51c/0x126e drivers/gpu/drm/virtio/virtgpu_kms.c:228
 virtio_gpu_probe+0x21c/0x360 drivers/gpu/drm/virtio/virtgpu_drv.c:103
 virtio_dev_probe+0x6a2/0xbe0 drivers/virtio/virtio.c:347
 call_driver_probe drivers/base/dd.c:628 [inline]
 really_probe+0x241/0xa60 drivers/base/dd.c:706
 __driver_probe_device+0x20e/0x450 drivers/base/dd.c:868
 driver_probe_device+0x4a/0x140 drivers/base/dd.c:898
 __device_attach_driver+0x1df/0x320 drivers/base/dd.c:1026
 bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:500
 __device_attach+0x1e4/0x4d0 drivers/base/dd.c:1098
 device_initial_probe+0xaf/0xd0 drivers/base/dd.c:1153
 bus_probe_device+0x64/0x160 drivers/base/bus.c:620
 device_add+0x121d/0x1970 drivers/base/core.c:3772
 register_virtio_device+0x4f0/0x5d0 drivers/virtio/virtio.c:568
 virtio_pci_probe+0x255/0x410 drivers/virtio/virtio_pci_common.c:722
 local_pci_probe+0xdd/0x1b0 drivers/pci/pci-driver.c:332
 pci_call_probe+0x176/0x800 drivers/pci/pci-driver.c:394
 __pci_device_probe drivers/pci/pci-driver.c:455 [inline]
 pci_device_probe+0x1cd/0x370 drivers/pci/pci-driver.c:489
 call_driver_probe drivers/base/dd.c:628 [inline]
 really_probe+0x241/0xa60 drivers/base/dd.c:706
 __driver_probe_device+0x20e/0x450 drivers/base/dd.c:868
 driver_probe_device+0x4a/0x140 drivers/base/dd.c:898
 __device_attach_driver+0x1df/0x320 drivers/base/dd.c:1026
 bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:500
 __device_attach+0x1e4/0x4d0 drivers/base/dd.c:1098
 device_initial_probe+0xaf/0xd0 drivers/base/dd.c:1153
 pci_bus_add_device+0xc5/0x100 drivers/pci/bus.c:373
 pci_bus_add_devices+0x9a/0x1f0 drivers/pci/bus.c:394
 pci_rescan_bus+0x2a/0x40 drivers/pci/probe.c:3500
 rescan_store+0xfb/0x130 drivers/pci/pci-sysfs.c:473
 bus_attr_store+0x74/0xb0 drivers/base/bus.c:172
 sysfs_kf_write+0xf2/0x150 fs/sysfs/file.c:145
 kernfs_fop_write_iter+0x3e0/0x5f0 fs/kernfs/file.c:345
 new_sync_write fs/read_write.c:595 [inline]
 vfs_write+0x6ac/0x1050 fs/read_write.c:687
 ksys_write+0x12a/0x250 fs/read_write.c:739
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fdf9279df99
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:00007fdf9365b028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fdf92a26090 RCX: 00007fdf9279df99
RDX: 0000000000000001 RSI: 0000200000000a00 RDI: 0000000000000004
RBP: 00007fdf92834ec4 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fdf92a26128 R14: 00007fdf92a26090 R15: 00007ffd5dc4ace8
 </TASK>
----------------
Code disassembly (best guess):
   0:	48 8b 43 60          	mov    0x60(%rbx),%rax
   4:	48 8d 58 a0          	lea    -0x60(%rax),%rbx
   8:	48 3d 30 82 d8 8e    	cmp    $0xffffffff8ed88230,%rax
   e:	74 1f                	je     0x2f
  10:	48 8b 7b 58          	mov    0x58(%rbx),%rdi
  14:	48 89 ee             	mov    %rbp,%rsi
  17:	e8 a5 a3 5d 09       	call   0x95da3c1
  1c:	85 c0                	test   %eax,%eax
  1e:	75 e0                	jne    0x0
  20:	48 8d 3d fa 2d ce 0e 	lea    0xece2dfa(%rip),%rdi        # 0xece2e21
  27:	48 89 ee             	mov    %rbp,%rsi
* 2a:	67 48 0f b9 3a       	ud1    (%edx),%rdi <-- trapping instruction
  2f:	be 20 00 00 00       	mov    $0x20,%esi
  34:	48 89 ef             	mov    %rbp,%rdi
  37:	e8 25 a5 5d 09       	call   0x95da561
  3c:	48 85 c0             	test   %rax,%rax
  3f:	0f                   	.byte 0xf

Crashes (22):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/07/30 14:38 upstream 11028ab62899 abc81b93 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in virtio_gpu_alloc_vbufs
2026/07/30 07:59 upstream fc46aed51f62 2377cd3d .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in virtio_gpu_alloc_vbufs
2026/07/30 02:28 upstream fc46aed51f62 2377cd3d .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in virtio_gpu_alloc_vbufs
2026/07/29 23:16 upstream fc02acf6ac0c 2377cd3d .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in virtio_gpu_alloc_vbufs
2026/07/29 21:04 upstream fc02acf6ac0c 2377cd3d .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in virtio_gpu_alloc_vbufs
2026/07/29 10:27 upstream fc02acf6ac0c 4a865b71 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in virtio_gpu_alloc_vbufs
2026/07/29 10:27 upstream fc02acf6ac0c 4a865b71 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in virtio_gpu_alloc_vbufs
2026/07/29 10:19 upstream 3b5f4b83c4ab 19622d9d .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in virtio_gpu_alloc_vbufs
2026/07/29 10:19 upstream 3b5f4b83c4ab 19622d9d .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in virtio_gpu_alloc_vbufs
2026/07/29 08:27 upstream 3b5f4b83c4ab 19622d9d .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in virtio_gpu_alloc_vbufs
2026/07/29 06:43 upstream 3b5f4b83c4ab 4a865b71 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in virtio_gpu_alloc_vbufs
2026/07/28 17:50 upstream 62cc90241548 4a865b71 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in virtio_gpu_alloc_vbufs
2026/07/28 13:20 upstream 62cc90241548 4a865b71 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in virtio_gpu_alloc_vbufs
2026/07/27 05:07 upstream 4235cb24ec1e 492bab15 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in virtio_gpu_alloc_vbufs
2026/07/26 23:26 upstream 4235cb24ec1e 492bab15 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in virtio_gpu_alloc_vbufs
2026/07/26 23:26 upstream 4235cb24ec1e 492bab15 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in virtio_gpu_alloc_vbufs
2026/07/26 23:05 upstream 4235cb24ec1e 4a865b71 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in virtio_gpu_alloc_vbufs
2026/07/26 05:07 upstream 3dab139d4795 4a865b71 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in virtio_gpu_alloc_vbufs
2026/07/26 01:28 upstream 3dab139d4795 4a865b71 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in virtio_gpu_alloc_vbufs
2026/07/25 20:25 upstream 3dab139d4795 4a865b71 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in virtio_gpu_alloc_vbufs
2026/07/25 12:25 upstream 0ce37745d4bf 4a865b71 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in virtio_gpu_alloc_vbufs
2026/07/25 09:28 upstream 0ce37745d4bf 4a865b71 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in virtio_gpu_alloc_vbufs
* Struck through repros no longer work on HEAD.