================================================================== BUG: KCSAN: data-race in exit_signals / kthread_unpark read-write to 0xffff88801941e02c of 4 bytes by task 21581 on cpu 0: exit_signals+0x102/0x530 kernel/signal.c:2862 do_exit+0x15d/0x1630 kernel/exit.c:779 kthread+0x205/0x220 kernel/kthread.c:294 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 read to 0xffff88801941e02c of 4 bytes by task 21576 on cpu 1: to_kthread kernel/kthread.c:83 [inline] kthread_unpark+0x1f/0x140 kernel/kthread.c:511 kthread_stop+0xa6/0x2c0 kernel/kthread.c:594 vivid_stop_generating_vid_cap+0x757/0x780 drivers/media/test-drivers/vivid/vivid-kthread-cap.c:1007 meta_cap_stop_streaming+0x4a/0x70 drivers/media/test-drivers/vivid/vivid-meta-cap.c:111 __vb2_queue_cancel+0x72/0x6c0 drivers/media/common/videobuf2/videobuf2-core.c:1937 vb2_core_streamoff drivers/media/common/videobuf2/videobuf2-core.c:2094 [inline] __vb2_cleanup_fileio drivers/media/common/videobuf2/videobuf2-core.c:2635 [inline] vb2_core_queue_release+0x35/0x190 drivers/media/common/videobuf2/videobuf2-core.c:2362 vb2_queue_release drivers/media/common/videobuf2/videobuf2-v4l2.c:944 [inline] _vb2_fop_release drivers/media/common/videobuf2/videobuf2-v4l2.c:1117 [inline] vb2_fop_release+0xee/0x150 drivers/media/common/videobuf2/videobuf2-v4l2.c:1131 vivid_fop_release+0x292/0x790 drivers/media/test-drivers/vivid/vivid-core.c:634 v4l2_release+0xfa/0x1f0 drivers/media/v4l2-core/v4l2-dev.c:452 __fput+0x24b/0x4e0 fs/file_table.c:280 ____fput+0x11/0x20 fs/file_table.c:313 task_work_run+0x8e/0x110 kernel/task_work.c:140 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop kernel/entry/common.c:174 [inline] exit_to_user_mode_prepare+0x16b/0x1a0 kernel/entry/common.c:201 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x20/0x40 kernel/entry/common.c:302 do_syscall_64+0x45/0x80 arch/x86/entry/common.c:56 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 21576 Comm: syz-executor.5 Not tainted 5.10.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================