WARNING in virtio_gpu_free_object

Status: upstream: reported C repro on 2026/09/02 13:38
Subsystems: dri virt
Labels: prio:high
[Documentation on labels]
Reported-by: syzbot+3590d97d8a586fa955c2@syzkaller.appspotmail.com
First crash: 49d, last: 1d15h
▶ ▼ ✨ AI Jobs (3)
ID Workflow Result Correct Bug Created Started Finished Revision
c27093ee repro-c 💥 WARNING in virtio_gpu_free_object 2026/09/04 08:26 2026/09/04 08:39 2026/09/04 09:35 801f0966
56a7e3b3 repro-c 💥 WARNING in virtio_gpu_free_object 2026/09/02 14:55 2026/09/02 14:55 2026/09/02 15:45 9941e97d
c9d7a283 assessment-security DenialOfService: ❌ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ✅ VMHostTrigger: ❌ ❓ WARNING in virtio_gpu_free_object 2026/08/31 00:02 2026/08/31 00:02 2026/08/31 00:08 2f52988a
▶ ▼ Discussions (2)
Title Replies (including bot) Last reply
[PATCH] drm/virtio: Destroy obj_restore_lock on the final drm_dev_put() 5 (5) 2026/10/14 21:03
[syzbot] [dri?] [virt?] WARNING in virtio_gpu_free_object 0 (2) 2026/09/28 14:21

Sample crash report:
Console: switching to colour dummy device 80x25
------------[ cut here ]------------
DEBUG_LOCKS_WARN_ON(lock->magic != lock)
WARNING: kernel/locking/mutex.c:625 at __mutex_lock_common kernel/locking/mutex.c:625 [inline], CPU#1: syz.0.17/5925
WARNING: kernel/locking/mutex.c:625 at __mutex_lock+0x944/0x1bd0 kernel/locking/mutex.c:821, CPU#1: syz.0.17/5925
Modules linked in:
CPU: 1 UID: 0 PID: 5925 Comm: syz.0.17 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:__mutex_lock_common kernel/locking/mutex.c:625 [inline]
RIP: 0010:__mutex_lock+0x94b/0x1bd0 kernel/locking/mutex.c:821
Code: 0f b6 14 11 38 d0 7c 08 84 d2 0f 85 c0 10 00 00 44 8b 05 c8 62 6f 06 45 85 c0 75 13 48 8d 3d cc 6e 72 06 48 c7 c6 c0 f6 ef 8b <67> 48 0f b9 3a 90 e9 1b f8 ff ff 4d 8d a7 f0 0a 00 00 4c 89 e7 e8
RSP: 0018:ffffc900033df980 EFLAGS: 00010246
RAX: 0000000000000003 RBX: ffff8881007351c0 RCX: 1ffffffff248b320
RDX: 0000000000000000 RSI: ffffffff8beff6c0 RDI: ffffffff9248a510
RBP: ffffc900033dfaf0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: dffffc0000000000 R15: ffff888029ad8b60
FS:  000055556c50c500(0000) GS:ffff8880d4a46000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000001380 CR3: 000000003d084000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 virtio_gpu_remove_from_restore_list drivers/gpu/drm/virtio/virtgpu_object.c:70 [inline]
 virtio_gpu_free_object+0xec/0x280 drivers/gpu/drm/virtio/virtgpu_object.c:106
 drm_gem_object_free+0x60/0xa0 drivers/gpu/drm/drm_gem.c:1164
 kref_put include/linux/kref.h:65 [inline]
 __drm_gem_object_put include/drm/drm_gem.h:562 [inline]
 drm_gem_object_put include/drm/drm_gem.h:575 [inline]
 drm_gem_object_put include/drm/drm_gem.h:572 [inline]
 drm_gem_object_handle_put_unlocked+0x20f/0x420 drivers/gpu/drm/drm_gem.c:357
 drm_gem_object_release_handle+0xc5/0x270 drivers/gpu/drm/drm_gem.c:384
 idr_for_each+0x143/0x270 lib/idr.c:210
 drm_gem_release+0x27/0x40 drivers/gpu/drm/drm_gem.c:1122
 drm_file_free.part.0+0x70b/0xcc0 drivers/gpu/drm/drm_file.c:261
 drm_file_free drivers/gpu/drm/drm_file.c:237 [inline]
 drm_close_helper.isra.0+0x186/0x200 drivers/gpu/drm/drm_file.c:290
 drm_release+0x1ab/0x360 drivers/gpu/drm/drm_file.c:438
 __fput+0x400/0xb60 fs/file_table.c:512
 task_work_run+0x150/0x240 kernel/task_work.c:233
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 __exit_to_user_mode_loop kernel/entry/common.c:70 [inline]
 exit_to_user_mode_loop+0x1d8/0x700 kernel/entry/common.c:101
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:343 [inline]
 do_syscall_64+0x661/0x790 arch/x86/entry/syscall_64.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff47d19e2d9
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:00007ffc02a2cd28 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007ffc02a2ce10 RCX: 00007ff47d19e2d9
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 000000000000e3d5 R08: 0000000000000001 R09: 0000000000000000
R10: 0000001b31f20000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff47d425fac R14: 00007ff47d425fa8 R15: 00007ff47d425fa0
 </TASK>
----------------
Code disassembly (best guess):
   0:	0f b6 14 11          	movzbl (%rcx,%rdx,1),%edx
   4:	38 d0                	cmp    %dl,%al
   6:	7c 08                	jl     0x10
   8:	84 d2                	test   %dl,%dl
   a:	0f 85 c0 10 00 00    	jne    0x10d0
  10:	44 8b 05 c8 62 6f 06 	mov    0x66f62c8(%rip),%r8d        # 0x66f62df
  17:	45 85 c0             	test   %r8d,%r8d
  1a:	75 13                	jne    0x2f
  1c:	48 8d 3d cc 6e 72 06 	lea    0x6726ecc(%rip),%rdi        # 0x6726eef
  23:	48 c7 c6 c0 f6 ef 8b 	mov    $0xffffffff8beff6c0,%rsi
* 2a:	67 48 0f b9 3a       	ud1    (%edx),%rdi <-- trapping instruction
  2f:	90                   	nop
  30:	e9 1b f8 ff ff       	jmp    0xfffff850
  35:	4d 8d a7 f0 0a 00 00 	lea    0xaf0(%r15),%r12
  3c:	4c 89 e7             	mov    %r12,%rdi
  3f:	e8                   	.byte 0xe8

Crashes (68):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/10/13 09:26 upstream 24a19b953e2a 5a1eeac4 .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in virtio_gpu_free_object
2026/09/28 14:21 upstream 72d3fcf802c4 a3c7249d .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in virtio_gpu_free_object
2026/10/16 00:27 upstream 045958acaa75 3f2522c6 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in virtio_gpu_free_object
2026/10/15 00:23 upstream 0fcb05b72344 8fb0ae89 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in virtio_gpu_free_object
2026/10/14 19:30 upstream 4056b3c9d3c9 1a71827b .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in virtio_gpu_free_object
2026/10/14 06:27 upstream ca3e345926b0 7321cd29 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in virtio_gpu_free_object
2026/10/13 17:41 upstream 24a19b953e2a 5a1eeac4 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in virtio_gpu_free_object
2026/10/12 17:06 upstream 24a19b953e2a 745a967f .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in virtio_gpu_free_object
2026/10/10 23:05 upstream 3857c2fe5449 4f92358f .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in virtio_gpu_free_object
2026/10/10 21:06 upstream 3857c2fe5449 4f92358f .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in virtio_gpu_free_object
2026/10/10 10:11 upstream 3857c2fe5449 4f92358f .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in virtio_gpu_free_object
2026/10/09 21:28 upstream af32da41b032 549ef7e3 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in virtio_gpu_free_object
2026/10/08 21:55 upstream 0c2669a9f4a1 9d4697fa .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in virtio_gpu_free_object
2026/10/07 13:54 upstream 602042bf29f6 6520ecdb .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in virtio_gpu_free_object
2026/10/06 13:27 upstream 2c3418fffa9d f7710056 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in virtio_gpu_free_object
2026/10/06 03:43 upstream 67f0943b394d f7710056 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in virtio_gpu_free_object
2026/10/05 11:28 upstream a90ee4305c4a 57bbd979 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in virtio_gpu_free_object
2026/10/05 09:59 upstream a90ee4305c4a 57bbd979 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in virtio_gpu_free_object
2026/10/05 03:36 upstream a90ee4305c4a 57bbd979 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in virtio_gpu_free_object
2026/10/05 00:07 upstream 6addb4f38557 57bbd979 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in virtio_gpu_free_object
2026/10/04 20:20 upstream 6addb4f38557 57bbd979 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in virtio_gpu_free_object
2026/10/03 23:50 upstream a74306e2e676 57bbd979 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in virtio_gpu_free_object
2026/10/03 06:36 upstream 3b7cab693ba2 57bbd979 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in virtio_gpu_free_object
2026/10/01 01:20 upstream 551c722f4080 15fb8e5e .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in virtio_gpu_free_object
2026/09/30 10:52 upstream 551c722f4080 7808aef4 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in virtio_gpu_free_object
2026/09/29 02:51 upstream 72d3fcf802c4 58f15308 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in virtio_gpu_free_object
2026/09/29 01:37 upstream 72d3fcf802c4 58f15308 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in virtio_gpu_free_object
2026/09/28 12:36 upstream 72d3fcf802c4 a3c7249d .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in virtio_gpu_free_object
2026/09/24 02:18 upstream 62f4c998b297 0a1606bc .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in virtio_gpu_free_object
2026/09/22 21:29 upstream c4e9f74da438 3e2106e5 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in virtio_gpu_free_object
2026/09/22 01:28 upstream f0100363d8c3 a8efa948 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in virtio_gpu_free_object
2026/09/21 17:15 upstream 93f51579e7df a8efa948 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in virtio_gpu_free_object
2026/09/20 20:52 upstream 518e5b794c06 853b104b .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in virtio_gpu_free_object
2026/09/19 07:26 upstream 40288c9206c1 853b104b .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in virtio_gpu_free_object
2026/09/18 15:29 upstream 5dd1818b15d9 853b104b .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in virtio_gpu_free_object
2026/09/18 09:28 upstream 4982d3552a3b 8d7d05f1 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in virtio_gpu_free_object
2026/09/17 20:42 upstream 4982d3552a3b 4a607247 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in virtio_gpu_free_object
2026/09/16 19:15 upstream 9b87fdc9af2f b0e4c57e .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in virtio_gpu_free_object
2026/09/16 18:36 upstream 9b87fdc9af2f b0e4c57e .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in virtio_gpu_free_object
2026/09/15 21:08 upstream f6e7b42bf05b f41e228a .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in virtio_gpu_free_object
2026/09/14 22:50 upstream 704340f1cd0d 924033e8 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in virtio_gpu_free_object
2026/09/14 22:09 upstream 704340f1cd0d 924033e8 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in virtio_gpu_free_object
2026/09/14 21:34 upstream 704340f1cd0d 924033e8 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in virtio_gpu_free_object
2026/09/14 21:06 upstream 704340f1cd0d 924033e8 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in virtio_gpu_free_object
2026/09/14 01:29 upstream d681d7ef617e 70a60e12 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in virtio_gpu_free_object
2026/09/11 15:11 upstream 08df884136f1 9c29f801 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in virtio_gpu_free_object
2026/09/11 04:33 upstream 50d05c7c76c9 1fe56c0a .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in virtio_gpu_free_object
2026/09/09 18:57 upstream 893e11787f78 edec9137 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in virtio_gpu_free_object
2026/09/09 16:39 upstream 893e11787f78 edec9137 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in virtio_gpu_free_object
2026/09/09 03:09 upstream 5acbae5f7eb3 8387c273 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in virtio_gpu_free_object
2026/09/08 18:07 upstream 5acbae5f7eb3 351387c4 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in virtio_gpu_free_object
2026/09/08 18:07 upstream 5acbae5f7eb3 351387c4 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in virtio_gpu_free_object
2026/09/08 03:38 upstream 28924df2a08f 680aa3e1 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in virtio_gpu_free_object
2026/09/07 21:27 upstream df2908090cda 5e4626f5 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in virtio_gpu_free_object
2026/09/07 14:57 upstream df2908090cda 5e4626f5 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in virtio_gpu_free_object
2026/09/06 17:15 upstream 1fc5a74b108f 4f7b22a0 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in virtio_gpu_free_object
2026/09/05 19:05 upstream 4d7d9486c04d 4f7b22a0 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in virtio_gpu_free_object
2026/09/05 06:58 upstream 654ae5d73c05 4f7b22a0 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in virtio_gpu_free_object
2026/09/05 05:13 upstream 654ae5d73c05 4f7b22a0 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in virtio_gpu_free_object
2026/09/01 16:38 upstream 786262be6048 587f6b29 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in virtio_gpu_free_object
2026/09/01 16:38 upstream 786262be6048 587f6b29 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in virtio_gpu_free_object
2026/08/31 06:02 upstream a23cbb05744b 2f52988a .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in virtio_gpu_free_object
2026/08/30 05:39 upstream 08dbfad3f504 2f52988a .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in virtio_gpu_free_object
2026/08/29 18:21 upstream cf72cbb39da8 2f52988a .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in virtio_gpu_free_object
2026/08/29 13:30 upstream cf72cbb39da8 2f52988a .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in virtio_gpu_free_object
* Struck through repros no longer work on HEAD.