------------[ cut here ]------------ WARNING: drivers/gpu/drm/vkms/vkms_crtc.c:97 at vkms_get_vblank_timestamp+0x137/0x160 drivers/gpu/drm/vkms/vkms_crtc.c:97, CPU#0: syz.9.1943/14750 Modules linked in: CPU: 0 UID: 0 PID: 14750 Comm: syz.9.1943 Not tainted 6.17.0-rc1-next-20250812-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:vkms_get_vblank_timestamp+0x137/0x160 drivers/gpu/drm/vkms/vkms_crtc.c:97 Code: 42 80 3c 28 00 74 08 48 89 df e8 b4 98 28 fc 4c 89 33 b0 01 5b 41 5c 41 5d 41 5e 41 5f 5d e9 d0 70 83 05 cc e8 ea 2f c5 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:ffffc9000bc4f668 EFLAGS: 00010293 RAX: ffffffff85fa7c56 RBX: ffffc9000bc4f7e0 RCX: ffff8880259fbc00 RDX: 0000000000000000 RSI: 000000e336a01e40 RDI: 000000e336a01e40 RBP: 1ffff92001789efc R08: ffffffff8fa3a137 R09: 1ffffffff1f47426 R10: dffffc0000000000 R11: ffffffff85fa7b20 R12: 000000e336a01e40 R13: dffffc0000000000 R14: ffff8880248c8028 R15: 000000e336a01e40 FS: 0000555563223500(0000) GS:ffff888125c13000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2ef21ff8 CR3: 000000005f7ac000 CR4: 00000000003526f0 Call Trace: drm_crtc_get_last_vbltimestamp drivers/gpu/drm/drm_vblank.c:879 [inline] drm_crtc_next_vblank_start+0x226/0x470 drivers/gpu/drm/drm_vblank.c:1013 set_fence_deadline drivers/gpu/drm/drm_atomic_helper.c:1711 [inline] drm_atomic_helper_wait_for_fences+0x265/0x8c0 drivers/gpu/drm/drm_atomic_helper.c:1758 commit_tail+0x79/0x3a0 drivers/gpu/drm/drm_atomic_helper.c:1972 drm_atomic_helper_commit+0xa6b/0xb10 drivers/gpu/drm/drm_atomic_helper.c:2226 drm_atomic_commit+0x25f/0x2c0 drivers/gpu/drm/drm_atomic.c:1577 drm_client_modeset_commit_atomic+0x620/0x760 drivers/gpu/drm/drm_client_modeset.c:1103 drm_client_modeset_commit_locked+0xcb/0x4d0 drivers/gpu/drm/drm_client_modeset.c:1206 drm_client_modeset_commit+0x4a/0x70 drivers/gpu/drm/drm_client_modeset.c:1232 __drm_fb_helper_restore_fbdev_mode_unlocked drivers/gpu/drm/drm_fb_helper.c:238 [inline] drm_fb_helper_restore_fbdev_mode_unlocked drivers/gpu/drm/drm_fb_helper.c:268 [inline] drm_fb_helper_lastclose+0xa4/0x1c0 drivers/gpu/drm/drm_fb_helper.c:1986 drm_fbdev_client_restore+0x34/0x40 drivers/gpu/drm/clients/drm_fbdev_client.c:31 drm_client_dev_restore+0x13c/0x270 drivers/gpu/drm/drm_client_event.c:117 drm_lastclose drivers/gpu/drm/drm_file.c:408 [inline] drm_release+0x318/0x3f0 drivers/gpu/drm/drm_file.c:441 __fput+0x44c/0xa70 fs/file_table.c:468 task_work_run+0x1d4/0x260 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop+0xec/0x110 kernel/entry/common.c:43 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f77b658ebe9 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:00007ffe21516378 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00000000000ee1ca RCX: 00007f77b658ebe9 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f77b67b7da0 R08: 0000000000000001 R09: 0000000c2151666f R10: 0000001b2df20000 R11: 0000000000000246 R12: 00007f77b67b5fac R13: 00007f77b67b5fa0 R14: ffffffffffffffff R15: 00007ffe21516490