sg_write: data in/out 393180/74 bytes for SCSI command 0xff-- guessing data in;
   program syz-executor5 not setting count and/or reply_len properly
sg_write: data in/out 393180/74 bytes for SCSI command 0xff-- guessing data in;
   program syz-executor5 not setting count and/or reply_len properly
==================================================================
BUG: KASAN: null-ptr-deref in atomic_inc include/asm-generic/atomic-instrumented.h:239 [inline]
BUG: KASAN: null-ptr-deref in kthread_stop+0x108/0x8f0 kernel/kthread.c:545
Write of size 4 at addr 000000000000001c by task syz-executor0/3826

CPU: 0 PID: 3826 Comm: syz-executor0 Not tainted 4.20.0-rc1-next-20181109+ #110
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+0x244/0x39d lib/dump_stack.c:113
 kasan_report_error mm/kasan/report.c:352 [inline]
 kasan_report.cold.8+0x6d/0x309 mm/kasan/report.c:412
 check_memory_region_inline mm/kasan/kasan.c:260 [inline]
 check_memory_region+0x13e/0x1b0 mm/kasan/kasan.c:267
 kasan_check_write+0x14/0x20 mm/kasan/kasan.c:278
 atomic_inc include/asm-generic/atomic-instrumented.h:239 [inline]
 kthread_stop+0x108/0x8f0 kernel/kthread.c:545
 vivid_stop_generating_vid_out+0x2bb/0x9ae drivers/media/platform/vivid/vivid-kthread-out.c:302
 vbi_out_stop_streaming+0x91/0x150 drivers/media/platform/vivid/vivid-vbi-out.c:114
 __vb2_queue_cancel+0x171/0xd20 drivers/media/common/videobuf2/videobuf2-core.c:1823
 vb2_core_streamoff+0x60/0x140 drivers/media/common/videobuf2/videobuf2-core.c:1980
 __vb2_cleanup_fileio+0x73/0x160 drivers/media/common/videobuf2/videobuf2-core.c:2501
 vb2_core_queue_release+0x1e/0x80 drivers/media/common/videobuf2/videobuf2-core.c:2228
 vb2_queue_release drivers/media/common/videobuf2/videobuf2-v4l2.c:837 [inline]
 _vb2_fop_release+0x1d2/0x2b0 drivers/media/common/videobuf2/videobuf2-v4l2.c:1010
 vb2_fop_release+0x77/0xc0 drivers/media/common/videobuf2/videobuf2-v4l2.c:1024
 vivid_fop_release+0x18e/0x440 drivers/media/platform/vivid/vivid-core.c:474
 v4l2_release+0x224/0x3a0 drivers/media/v4l2-core/v4l2-dev.c:456
 __fput+0x3bc/0xa70 fs/file_table.c:279
 ____fput+0x15/0x20 fs/file_table.c:312
 task_work_run+0x1e8/0x2a0 kernel/task_work.c:113
 get_signal+0x1550/0x1970 kernel/signal.c:2347
 do_signal+0x9c/0x21c0 arch/x86/kernel/signal.c:816
 exit_to_usermode_loop+0x2e5/0x380 arch/x86/entry/common.c:162
 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:268 [inline]
 do_syscall_64+0x6be/0x820 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457569
Code: fd b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 cb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007feabcab7c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: 0000000000019500 RBX: 0000000000000004 RCX: 0000000000457569
RDX: 00000000200000c0 RSI: 0000000000000006 RDI: 0000000000000005
RBP: 000000000072bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000effffdef R11: 0000000000000246 R12: 00007feabcab86d4
R13: 00000000004c3c2a R14: 00000000004d6230 R15: 00000000ffffffff
==================================================================