------------[ cut here ]------------
WARNING: CPU: 0 PID: 535 at drivers/gpu/drm/vkms/vkms_crtc.c:103 vkms_get_vblank_timestamp+0x1cf/0x240 drivers/gpu/drm/vkms/vkms_crtc.c:103
Modules linked in:
CPU: 0 PID: 535 Comm: syz-executor.5 Not tainted 6.4.0-rc3-syzkaller-00008-gae8373a5add4 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/28/2023
RIP: 0010:vkms_get_vblank_timestamp+0x1cf/0x240 drivers/gpu/drm/vkms/vkms_crtc.c:103
Code: b0 70 fc e8 f3 ba 60 fc 4c 89 e1 48 ba 00 00 00 00 00 fc ff df 48 c1 e9 03 80 3c 11 00 75 65 49 89 04 24 eb c4 e8 d1 b0 70 fc <0f> 0b eb bb e8 78 7a c3 fc e9 de fe ff ff e8 ae 7a c3 fc e9 78 fe
RSP: 0018:ffffc900035073e0 EFLAGS: 00010216
RAX: 00000000000019de RBX: 0000021bcfc43ebb RCX: ffffc9000f408000
RDX: 0000000000040000 RSI: ffffffff851391ff RDI: 0000000000000006
RBP: ffff88801ef3c000 R08: 0000000000000006 R09: 0000021bcfc43ebb
R10: 0000021bcfc43ebb R11: 0000000000000000 R12: ffffc90003507548
R13: 0000021bcfc43ebb R14: 0000000000004e20 R15: ffffffff85139030
FS:  00007fb62e57a700(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7ef70350a0 CR3: 000000002a4d9000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 drm_crtc_get_last_vbltimestamp+0x102/0x1a0 drivers/gpu/drm/drm_vblank.c:877
 drm_crtc_next_vblank_start+0x186/0x300 drivers/gpu/drm/drm_vblank.c:1012
 set_fence_deadline drivers/gpu/drm/drm_atomic_helper.c:1537 [inline]
 drm_atomic_helper_wait_for_fences+0x1f3/0x840 drivers/gpu/drm/drm_atomic_helper.c:1584
 commit_tail+0x85/0x420 drivers/gpu/drm/drm_atomic_helper.c:1798
 drm_atomic_helper_commit drivers/gpu/drm/drm_atomic_helper.c:2052 [inline]
 drm_atomic_helper_commit+0x2ef/0x370 drivers/gpu/drm/drm_atomic_helper.c:1985
 drm_atomic_commit+0x20a/0x300 drivers/gpu/drm/drm_atomic.c:1503
 drm_client_modeset_commit_atomic+0x69b/0x7e0 drivers/gpu/drm/drm_client_modeset.c:1045
 drm_client_modeset_commit_locked+0x149/0x580 drivers/gpu/drm/drm_client_modeset.c:1148
 pan_display_atomic drivers/gpu/drm/drm_fb_helper.c:1726 [inline]
 drm_fb_helper_pan_display+0x28f/0x970 drivers/gpu/drm/drm_fb_helper.c:1786
 fb_pan_display+0x2fb/0x6c0 drivers/video/fbdev/core/fbmem.c:924
 fb_set_var+0x749/0x1090 drivers/video/fbdev/core/fbmem.c:1056
 do_fb_ioctl+0x6a0/0x750 drivers/video/fbdev/core/fbmem.c:1125
 fb_ioctl+0xeb/0x150 drivers/video/fbdev/core/fbmem.c:1204
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl fs/ioctl.c:856 [inline]
 __x64_sys_ioctl+0x197/0x210 fs/ioctl.c:856
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fb62fe8c169
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 00 00 90 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fb62e57a168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fb62ffac2c0 RCX: 00007fb62fe8c169
RDX: 0000000020000000 RSI: 0000000000004601 RDI: 0000000000000007
RBP: 00007fb62fee7ca1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffcd827757f R14: 00007fb62e57a300 R15: 0000000000022000
 </TASK>