------------[ cut here ]------------
WARNING: CPU: 0 PID: 9636 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: 0 UID: 0 PID: 9636 Comm: syz.2.1072 Not tainted 6.14.0-syzkaller-01103-g2df0c02dab82 #0 PREEMPT(full) 
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 38 2b f1 fb 48 89 5d 00 b0 01 5b 41 5c 41 5d 41 5e 41 5f 5d e9 6e e9 d5 fa e8 2e 0b 89 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:ffffc900043d6fa8 EFLAGS: 00010287
RAX: ffffffff863a57a2 RBX: 0000005c61e60141 RCX: 0000000000080000
RDX: ffffc9000e971000 RSI: 0000000000003071 RDI: 0000000000003072
RBP: ffffc900043d7140 R08: ffffffff863a570f R09: 1ffffffff2079fae
R10: dffffc0000000000 R11: ffffffff863a5620 R12: 0000005c61e60141
R13: ffff888146ec4150 R14: 1ffff9200087ae28 R15: ffff888024dfc000
FS:  00007f7b68e896c0(0000) GS:ffff888125224000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000010000 CR3: 0000000022f22000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 drm_crtc_get_last_vbltimestamp drivers/gpu/drm/drm_vblank.c:878 [inline]
 drm_crtc_next_vblank_start+0x257/0x4f0 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+0x27c/0x8e0 drivers/gpu/drm/drm_atomic_helper.c:1605
 commit_tail+0x75/0x3d0 drivers/gpu/drm/drm_atomic_helper.c:1819
 drm_atomic_helper_commit+0x95d/0xa00 drivers/gpu/drm/drm_atomic_helper.c:2073
 drm_atomic_commit+0x298/0x2f0 drivers/gpu/drm/drm_atomic.c:1518
 drm_client_modeset_commit_atomic+0x677/0x7d0 drivers/gpu/drm/drm_client_modeset.c:1079
 drm_client_modeset_commit_locked+0xe0/0x520 drivers/gpu/drm/drm_client_modeset.c:1182
 pan_display_atomic drivers/gpu/drm/drm_fb_helper.c:1379 [inline]
 drm_fb_helper_pan_display+0x3e8/0xc20 drivers/gpu/drm/drm_fb_helper.c:1439
 fb_pan_display+0x3a5/0x680 drivers/video/fbdev/core/fbmem.c:191
 bit_update_start+0x4d/0x1c0 drivers/video/fbdev/core/bitblit.c:381
 fbcon_switch+0x144f/0x2260 drivers/video/fbdev/core/fbcon.c:2186
 redraw_screen+0x55c/0xed0 drivers/tty/vt/vt.c:957
 fbcon_do_set_font+0xd4b/0x1410 drivers/video/fbdev/core/fbcon.c:2451
 con_font_set drivers/tty/vt/vt.c:4802 [inline]
 con_font_op+0xe97/0x1350 drivers/tty/vt/vt.c:4849
 vt_k_ioctl drivers/tty/vt/vt_ioctl.c:474 [inline]
 vt_ioctl+0x1c2b/0x2010 drivers/tty/vt/vt_ioctl.c:751
 tty_ioctl+0x911/0xdc0 drivers/tty/tty_io.c:2802
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:906 [inline]
 __se_sys_ioctl+0xf3/0x160 fs/ioctl.c:892
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f7b67f8d169
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:00007f7b68e89038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f7b681a6080 RCX: 00007f7b67f8d169
RDX: 0000200000000000 RSI: 0000000000004b72 RDI: 0000000000000005
RBP: 00007f7b6800e2a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f7b681a6080 R15: 00007ffedea751d8
 </TASK>