------------[ cut here ]------------
WARNING: CPU: 1 PID: 8492 at drivers/gpu/drm/vkms/vkms_crtc.c:97 vkms_get_vblank_timestamp+0x167/0x1b0 drivers/gpu/drm/vkms/vkms_crtc.c:97
Modules linked in:
CPU: 1 UID: 0 PID: 8492 Comm: syz.4.832 Not tainted 6.15.0-syzkaller-11796-g5abc7438f1e9 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:vkms_get_vblank_timestamp+0x167/0x1b0 drivers/gpu/drm/vkms/vkms_crtc.c:97
Code: b9 fb e8 3c cc a6 fb 4c 89 e1 48 ba 00 00 00 00 00 fc ff df 48 c1 e9 03 80 3c 11 00 75 43 49 89 04 24 eb c0 e8 7a 5f b9 fb 90 <0f> 0b 90 eb b5 e8 cf 16 20 fc e9 dc fe ff ff e8 55 17 20 fc e9 14
RSP: 0018:ffffc9000415f7e8 EFLAGS: 00010293
RAX: 0000000000000000 RBX: ffff888025cf8028 RCX: ffffffff8602b66e
RDX: ffff888029d28000 RSI: ffffffff8602b6e6 RDI: 0000000000000006
RBP: 000000325deaa798 R08: 0000000000000006 R09: 000000325deaa798
R10: 000000325deaa798 R11: 0000000000000000 R12: ffffc9000415f950
R13: 000000325deaa798 R14: 0000000000004e20 R15: ffffffff8602b580
FS:  00005555793dc500(0000) GS:ffff888124865000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f62669d4f98 CR3: 0000000034b0f000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 drm_crtc_get_last_vbltimestamp+0x105/0x1b0 drivers/gpu/drm/drm_vblank.c:878
 drm_crtc_next_vblank_start+0x182/0x300 drivers/gpu/drm/drm_vblank.c:1012
 set_fence_deadline drivers/gpu/drm/drm_atomic_helper.c:1596 [inline]
 drm_atomic_helper_wait_for_fences+0x203/0x830 drivers/gpu/drm/drm_atomic_helper.c:1643
 drm_atomic_helper_commit+0x1cf/0x380 drivers/gpu/drm/drm_atomic_helper.c:2072
 drm_atomic_commit+0x231/0x300 drivers/gpu/drm/drm_atomic.c:1577
 drm_client_modeset_commit_atomic+0x69d/0x7e0 drivers/gpu/drm/drm_client_modeset.c:1101
 drm_client_modeset_commit_locked+0x14d/0x580 drivers/gpu/drm/drm_client_modeset.c:1204
 drm_client_modeset_commit+0x4f/0x80 drivers/gpu/drm/drm_client_modeset.c:1230
 __drm_fb_helper_restore_fbdev_mode_unlocked drivers/gpu/drm/drm_fb_helper.c:237 [inline]
 __drm_fb_helper_restore_fbdev_mode_unlocked+0x19f/0x200 drivers/gpu/drm/drm_fb_helper.c:216
 drm_fbdev_client_restore+0x2c/0x40 drivers/gpu/drm/clients/drm_fbdev_client.c:31
 drm_client_dev_restore+0x1f3/0x2a0 drivers/gpu/drm/drm_client_event.c:116
 drm_lastclose drivers/gpu/drm/drm_file.c:396 [inline]
 drm_release+0x2c4/0x360 drivers/gpu/drm/drm_file.c:429
 __fput+0x402/0xb70 fs/file_table.c:465
 task_work_run+0x14d/0x240 kernel/task_work.c:227
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop+0xeb/0x110 kernel/entry/common.c:114
 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline]
 do_syscall_64+0x3f6/0x4c0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe85ed8e969
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:00007fff9084aa78 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007fe85efb7ba0 RCX: 00007fe85ed8e969
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007fe85efb7ba0 R08: 0000000000005314 R09: 000000159084ad6f
R10: 00007fe85efb7ac0 R11: 0000000000000246 R12: 0000000000034a77
R13: 00007fe85efb6160 R14: ffffffffffffffff R15: 00007fff9084ab90
 </TASK>