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BUG: KASAN: null-ptr-deref in atomic_inc include/asm-generic/atomic-instrumented.h:109 [inline]
BUG: KASAN: null-ptr-deref in kthread_stop+0x78/0x6d0 kernel/kthread.c:545
Write of size 4 at addr 0000000000000020 by task syz-executor.1/3354

CPU: 1 PID: 3354 Comm: syz-executor.1 Not tainted 4.19.44 #16
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+0x172/0x1f0 lib/dump_stack.c:113
 kasan_report_error mm/kasan/report.c:352 [inline]
 kasan_report mm/kasan/report.c:412 [inline]
 kasan_report.cold+0x199/0x2ba mm/kasan/report.c:396
 check_memory_region_inline mm/kasan/kasan.c:260 [inline]
 check_memory_region+0x123/0x190 mm/kasan/kasan.c:267
 kasan_check_write+0x14/0x20 mm/kasan/kasan.c:278
 atomic_inc include/asm-generic/atomic-instrumented.h:109 [inline]
 kthread_stop+0x78/0x6d0 kernel/kthread.c:545
 vivid_stop_generating_vid_cap+0x1e0/0x6e2 drivers/media/platform/vivid/vivid-kthread-cap.c:922
 vid_cap_stop_streaming+0x8a/0xe0 drivers/media/platform/vivid/vivid-vid-cap.c:256
 __vb2_queue_cancel+0xb1/0x960 drivers/media/common/videobuf2/videobuf2-core.c:1662
 vb2_core_streamoff+0x60/0x140 drivers/media/common/videobuf2/videobuf2-core.c:1796
 __vb2_cleanup_fileio+0x78/0x170 drivers/media/common/videobuf2/videobuf2-core.c:2323
 vb2_core_queue_release+0x20/0x80 drivers/media/common/videobuf2/videobuf2-core.c:2050
 vb2_queue_release drivers/media/common/videobuf2/videobuf2-v4l2.c:671 [inline]
 _vb2_fop_release+0x1cf/0x2a0 drivers/media/common/videobuf2/videobuf2-v4l2.c:842
 vb2_fop_release+0x75/0xc0 drivers/media/common/videobuf2/videobuf2-v4l2.c:856
 vivid_fop_release+0x18e/0x430 drivers/media/platform/vivid/vivid-core.c:474
 v4l2_release+0xf9/0x1a0 drivers/media/v4l2-core/v4l2-dev.c:448
 __fput+0x2dd/0x8b0 fs/file_table.c:278
 ____fput+0x16/0x20 fs/file_table.c:309
 task_work_run+0x145/0x1c0 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:193 [inline]
 exit_to_usermode_loop+0x273/0x2c0 arch/x86/entry/common.c:167
 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:271 [inline]
 do_syscall_64+0x53d/0x620 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x412f61
Code: 75 14 b8 03 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 04 1b 00 00 c3 48 83 ec 08 e8 0a fc ff ff 48 89 04 24 b8 03 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 53 fc ff ff 48 89 d0 48 83 c4 08 48 3d 01
RSP: 002b:00007ffe8ab34140 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000006 RCX: 0000000000412f61
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000005
RBP: 0000000000000001 R08: 00000000f1ce6625 R09: 00000000f1ce6629
R10: 00007ffe8ab34220 R11: 0000000000000293 R12: 0000000000760db8
R13: 000000000015b51b R14: 000000000015b548 R15: 000000000075bf2c
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