------------[ cut here ]------------
WARNING: CPU: 1 PID: 18201 at drivers/gpu/drm/vkms/vkms_crtc.c:97 vkms_get_vblank_timestamp+0x137/0x160
Modules linked in:
CPU: 1 UID: 0 PID: 18201 Comm: syz.0.4683 Not tainted 6.17.0-rc1-syzkaller-00036-gdfc0f6373094-dirty #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:vkms_get_vblank_timestamp+0x137/0x160
Code: 42 80 3c 28 00 74 08 48 89 df e8 74 50 2a fc 4c 89 33 b0 01 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc e8 1a e6 c6 fb 90 <0f> 0b 90 eb e3 44 89 e1 80 e1 07 38 c1 0f 8c ff fe ff ff 4c 89 e7
RSP: 0018:ffffc90003f5f668 EFLAGS: 00010293
RAX: ffffffff85f8c576 RBX: ffffc90003f5f7e0 RCX: ffff888020f63980
RDX: 0000000000000000 RSI: 000000700ebcb210 RDI: 000000700ebcb210
RBP: 1ffff920007ebefc R08: ffffffff8fa37e37 R09: 1ffffffff1f46fc6
R10: dffffc0000000000 R11: ffffffff85f8c440 R12: 000000700ebcb210
R13: dffffc0000000000 R14: ffff8881083f0028 R15: 000000700ebcb210
FS:  000055557ecbf500(0000) GS:ffff8881a3c1c000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b31c23ffc CR3: 000000010c26e000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 drm_crtc_next_vblank_start+0x226/0x470
 drm_atomic_helper_wait_for_fences+0x265/0x8c0
 commit_tail+0x79/0x3a0
 drm_atomic_helper_commit+0xa6b/0xb10
 drm_atomic_commit+0x262/0x2c0
 drm_client_modeset_commit_atomic+0x620/0x760
 drm_client_modeset_commit_locked+0xcb/0x4d0
 drm_client_modeset_commit+0x4a/0x70
 drm_fb_helper_lastclose+0xa4/0x1c0
 drm_fbdev_client_restore+0x34/0x40
 drm_client_dev_restore+0x13c/0x270
 drm_release+0x318/0x3f0
 __fput+0x44c/0xa70
 task_work_run+0x1d4/0x260
 exit_to_user_mode_loop+0xec/0x110
 do_syscall_64+0x2bd/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0d7fb8ebe9
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:00007ffdc0abe868 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00000000000757fc RCX: 00007f0d7fb8ebe9
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f0d7fdb7da0 R08: 0000000000000001 R09: 00000002c0abeb5f
R10: 0000001b30c20000 R11: 0000000000000246 R12: 00007f0d7fdb5fac
R13: 00007f0d7fdb5fa0 R14: ffffffffffffffff R15: 00007ffdc0abe980
 </TASK>
