------------[ cut here ]------------
WARNING: CPU: 1 PID: 17987 at drivers/gpu/drm/vkms/vkms_crtc.c:98 vkms_get_vblank_timestamp+0x183/0x1b0 drivers/gpu/drm/vkms/vkms_crtc.c:98
Modules linked in:
CPU: 1 UID: 0 PID: 17987 Comm: syz.6.1511 Not tainted 6.14.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
RIP: 0010:vkms_get_vblank_timestamp+0x183/0x1b0 drivers/gpu/drm/vkms/vkms_crtc.c:98
Code: 42 80 3c 30 00 74 08 48 89 ef e8 f8 a7 f7 fb 48 89 5d 00 b0 01 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc e8 ae 6c 90 fb 90 <0f> 0b 90 eb e4 89 d9 80 e1 07 38 c1 0f 8c cd fe ff ff 48 89 df e8
RSP: 0018:ffffc9000b9df2e8 EFLAGS: 00010293
RAX: ffffffff86315152 RBX: 0000008afffeb044 RCX: ffff88802b0d3c00
RDX: 0000000000000000 RSI: 0000008afffeb044 RDI: 0000008afffeb044
RBP: ffffc9000b9df480 R08: ffffffff863150bf R09: 0000000000000000
R10: ffffc90003759000 R11: ffffffff86314fd0 R12: 0000008afffeb044
R13: ffff88814237f150 R14: 1ffff9200173be90 R15: ffff8880250d4000
FS:  0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055a5c805f131 CR3: 000000007e126000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 drm_crtc_get_last_vbltimestamp drivers/gpu/drm/drm_vblank.c:878 [inline]
 drm_crtc_next_vblank_start+0x229/0x490 drivers/gpu/drm/drm_vblank.c:1012
 set_fence_deadline drivers/gpu/drm/drm_atomic_helper.c:1558 [inline]
 drm_atomic_helper_wait_for_fences+0x277/0x8e0 drivers/gpu/drm/drm_atomic_helper.c:1605
 drm_atomic_helper_commit+0x53a/0x9f0 drivers/gpu/drm/drm_atomic_helper.c:2034
 drm_atomic_commit+0x294/0x2f0 drivers/gpu/drm/drm_atomic.c:1518
 drm_client_modeset_commit_atomic+0x670/0x7d0 drivers/gpu/drm/drm_client_modeset.c:1079
 drm_client_modeset_commit_locked+0xe0/0x520 drivers/gpu/drm/drm_client_modeset.c:1182
 drm_client_modeset_commit+0x4a/0x70 drivers/gpu/drm/drm_client_modeset.c:1208
 __drm_fb_helper_restore_fbdev_mode_unlocked drivers/gpu/drm/drm_fb_helper.c:237 [inline]
 drm_fb_helper_restore_fbdev_mode_unlocked drivers/gpu/drm/drm_fb_helper.c:264 [inline]
 drm_fb_helper_lastclose+0xbb/0x180 drivers/gpu/drm/drm_fb_helper.c:1977
 drm_fbdev_client_restore+0x34/0x40 drivers/gpu/drm/clients/drm_fbdev_client.c:31
 drm_client_dev_restore+0x132/0x270 drivers/gpu/drm/drm_client_event.c:104
 drm_lastclose drivers/gpu/drm/drm_file.c:396 [inline]
 drm_release+0x335/0x410 drivers/gpu/drm/drm_file.c:429
 __fput+0x3e9/0x9f0 fs/file_table.c:464
 task_work_run+0x24f/0x310 kernel/task_work.c:227
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0xa2a/0x28e0 kernel/exit.c:938
 do_group_exit+0x207/0x2c0 kernel/exit.c:1087
 get_signal+0x168c/0x1720 kernel/signal.c:3036
 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0xce/0x340 kernel/entry/common.c:218
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>