------------[ 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#0: syz.2.3/5871 WARNING: kernel/locking/mutex.c:625 at __mutex_lock+0x944/0x1bd0 kernel/locking/mutex.c:821, CPU#0: syz.2.3/5871 Modules linked in: CPU: 0 UID: 0 PID: 5871 Comm: syz.2.3 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 e8 e8 70 05 45 85 c0 75 13 48 8d 3d ec f4 73 05 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:ffffc90003b6fb30 EFLAGS: 00010246 RAX: 0000000000000003 RBX: ffff8881007151c0 RCX: 1ffffffff228b1e0 RDX: 0000000000000000 RSI: ffffffff8beff6c0 RDI: ffffffff91489b10 RBP: ffffc90003b6fca0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000 R13: 0000000000000000 R14: dffffc0000000000 R15: ffff888028058360 FS: 00005555863df500(0000) GS:ffff8880d5b4e000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b329e4ff8 CR3: 0000000056bb6000 CR4: 0000000000352ef0 Call Trace: 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_client_buffer_delete drivers/gpu/drm/drm_client.c:201 [inline] drm_client_buffer_delete+0x1d8/0x270 drivers/gpu/drm/drm_client.c:185 drm_fbdev_shmem_fb_destroy+0xc5/0x110 drivers/gpu/drm/drm_fbdev_shmem.c:67 put_fb_info drivers/video/fbdev/core/fbmem.c:61 [inline] put_fb_info+0xb8/0xf0 drivers/video/fbdev/core/fbmem.c:56 fb_release+0x13e/0x190 drivers/video/fbdev/core/fb_chrdev.c:381 __fput+0x3ff/0xb50 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: 0033:0x7f1c9499e159 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:00007ffd935ebcf8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007f1c94c27da0 RCX: 00007f1c9499e159 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f1c94c27da0 R08: 00007f1c94c26038 R09: 0000000000000000 R10: 00000000005c025c R11: 0000000000000246 R12: 0000000000009c8b R13: 00007f1c94c2609c R14: 00000000000099eb R15: 00007f1c94c26090 ---------------- 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 e8 e8 70 05 mov 0x570e8e8(%rip),%r8d # 0x570e8ff 17: 45 85 c0 test %r8d,%r8d 1a: 75 13 jne 0x2f 1c: 48 8d 3d ec f4 73 05 lea 0x573f4ec(%rip),%rdi # 0x573f50f 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