INFO: trying to register non-static key.
the code is fine but needs lockdep annotation.
turning off the locking correctness validator.
CPU: 0 PID: 8240 Comm: syz-executor791 Not tainted 4.20.0+ #167
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1d3/0x2c6 lib/dump_stack.c:113
 assign_lock_key kernel/locking/lockdep.c:727 [inline]
 register_lock_class+0x21c5/0x29d0 kernel/locking/lockdep.c:753
 __lock_acquire+0x184/0x4c20 kernel/locking/lockdep.c:3227
 lock_acquire+0x1ed/0x520 kernel/locking/lockdep.c:3844
 __flush_work+0x752/0x9b0 kernel/workqueue.c:2912
 flush_work+0x17/0x20 kernel/workqueue.c:2938
 vkms_atomic_crtc_destroy_state+0x2b/0x40 drivers/gpu/drm/vkms/vkms_crtc.c:139
 drm_atomic_state_default_clear+0x37c/0xda0 drivers/gpu/drm/drm_atomic.c:171
 drm_atomic_state_clear+0x9f/0xd0 drivers/gpu/drm/drm_atomic.c:240
 __drm_atomic_state_free+0x3a/0xf0 drivers/gpu/drm/drm_atomic.c:256
 kref_put include/linux/kref.h:70 [inline]
 drm_atomic_state_put include/drm/drm_atomic.h:385 [inline]
 drm_atomic_helper_set_config+0xe6/0x160 drivers/gpu/drm/drm_atomic_helper.c:2947
 drm_mode_setcrtc+0x767/0x1890 drivers/gpu/drm/drm_crtc.c:748
 drm_ioctl_kernel+0x278/0x330 drivers/gpu/drm/drm_ioctl.c:758
 drm_ioctl+0x58f/0xb90 drivers/gpu/drm/drm_ioctl.c:858
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:509 [inline]
 do_vfs_ioctl+0x1de/0x1790 fs/ioctl.c:696
 ksys_ioctl+0xa9/0xd0 fs/ioctl.c:713
 __do_sys_ioctl fs/ioctl.c:720 [inline]
 __se_sys_ioctl fs/ioctl.c:718 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x443e59
Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 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 0f 83 7b d8 fb ff c3 66 2e 0f 1f 84 00 00 00 00