BUG: unable to handle kernel NULL pointer dereference at 0000000000000020 IP: atomic_inc arch/x86/include/asm/atomic.h:92 [inline] IP: kthread_stop+0x4c/0x650 kernel/kthread.c:525 PGD 9a783067 P4D 9a783067 PUD 8d02b067 PMD 0 Oops: 0002 [#1] PREEMPT SMP KASAN Modules linked in: CPU: 0 PID: 18008 Comm: syz-executor.4 Not tainted 4.14.134 #29 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff88805f3ac6c0 task.stack: ffff8880a5b48000 kobject: 'loop5' (ffff8880a4a63320): kobject_uevent_env RIP: 0010:atomic_inc arch/x86/include/asm/atomic.h:92 [inline] RIP: 0010:kthread_stop+0x4c/0x650 kernel/kthread.c:525 RSP: 0018:ffff8880a5b4fb50 EFLAGS: 00010297 kobject: 'loop5' (ffff8880a4a63320): fill_kobj_path: path = '/devices/virtual/block/loop5' RAX: ffff88805f3ac6c0 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 00000000ffffffff RDI: 0000000000000282 RBP: ffff8880a5b4fb70 R08: ffff88805f3ac6c0 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: ffff88805f3de270 R14: ffff88805f3de268 R15: ffffffff89bbaba0 FS: 0000000000ca7940(0000) GS:ffff8880aee00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000020 CR3: 000000005b6f5000 CR4: 00000000001426f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 kobject: 'loop5' (ffff8880a4a63320): kobject_uevent_env DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 kobject: 'loop5' (ffff8880a4a63320): fill_kobj_path: path = '/devices/virtual/block/loop5' Call Trace: vivid_stop_generating_vid_cap+0x1b9/0x664 drivers/media/platform/vivid/vivid-kthread-cap.c:934 kobject: 'loop5' (ffff8880a4a63320): kobject_uevent_env vid_cap_stop_streaming+0x7c/0xd0 drivers/media/platform/vivid/vivid-vid-cap.c:273 __vb2_queue_cancel+0xa3/0x890 drivers/media/v4l2-core/videobuf2-core.c:1655 kobject: 'loop5' (ffff8880a4a63320): fill_kobj_path: path = '/devices/virtual/block/loop5' vb2_core_streamoff+0x52/0x110 drivers/media/v4l2-core/videobuf2-core.c:1788 __vb2_cleanup_fileio+0x78/0x150 drivers/media/v4l2-core/videobuf2-core.c:2313 vb2_core_queue_release+0x1d/0x80 drivers/media/v4l2-core/videobuf2-core.c:2040 vb2_queue_release drivers/media/v4l2-core/videobuf2-v4l2.c:669 [inline] _vb2_fop_release+0x1cf/0x2a0 drivers/media/v4l2-core/videobuf2-v4l2.c:840 vb2_fop_release+0x75/0xc0 drivers/media/v4l2-core/videobuf2-v4l2.c:854 vivid_fop_release+0x180/0x3f0 drivers/media/platform/vivid/vivid-core.c:486 kobject: 'loop2' (ffff8880a496e920): kobject_uevent_env v4l2_release+0xf9/0x190 drivers/media/v4l2-core/v4l2-dev.c:446 kobject: 'loop2' (ffff8880a496e920): fill_kobj_path: path = '/devices/virtual/block/loop2' __fput+0x275/0x7a0 fs/file_table.c:210 ____fput+0x16/0x20 fs/file_table.c:244 task_work_run+0x114/0x190 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:191 [inline] exit_to_usermode_loop+0x1da/0x220 arch/x86/entry/common.c:164 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline] syscall_return_slowpath arch/x86/entry/common.c:270 [inline] do_syscall_64+0x4bc/0x640 arch/x86/entry/common.c:297 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x413511 RSP: 002b:00007ffd1f4ffbf0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000004 RCX: 0000000000413511 RDX: 0000001b2db20000 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 0000000000000001 R08: ffffffff812a8201 R09: 00000000e453ba3f R10: 00007ffd1f4ffcd0 R11: 0000000000000293 R12: 000000000075bfc8 R13: 000000000005609e R14: 0000000000760e58 R15: ffffffffffffffff Code: 00 65 8b 1d 37 6d c3 7e 83 fb 3f 0f 87 5e 04 00 00 e8 f9 92 1e 00 89 db 48 0f a3 1d cf 16 e7 06 0f 82 47 03 00 00 e8 e4 92 1e 00 41 ff 44 24 20 49 8d 7c 24 24 48 b8 00 00 00 00 00 fc ff df RIP: atomic_inc arch/x86/include/asm/atomic.h:92 [inline] RSP: ffff8880a5b4fb50 RIP: kthread_stop+0x4c/0x650 kernel/kthread.c:525 RSP: ffff8880a5b4fb50 CR2: 0000000000000020 kobject: 'loop1' (ffff8880a4922f20): kobject_uevent_env kobject: 'loop1' (ffff8880a4922f20): fill_kobj_path: path = '/devices/virtual/block/loop1' ---[ end trace 88713bebc0233ecd ]---