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 7f3db067 P4D 7f3db067 PUD 95438067 PMD 0 
Oops: 0002 [#1] PREEMPT SMP KASAN
Modules linked in:
CPU: 1 PID: 7327 Comm: syz-executor.0 Not tainted 4.14.116 #6
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff88807c2260c0 task.stack: ffff888057ed0000
RIP: 0010:atomic_inc arch/x86/include/asm/atomic.h:92 [inline]
RIP: 0010:kthread_stop+0x4c/0x650 kernel/kthread.c:525
RSP: 0018:ffff888057ed7b88 EFLAGS: 00010212
RAX: 0000000000040000 RBX: 0000000000000001 RCX: ffffc90006e45000
RDX: 0000000000000468 RSI: ffffffff813e6c9c RDI: 0000000000000282
RBP: ffff888057ed7ba8 R08: ffff88807c2260c0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: ffff88809f1a3d38 R14: ffff8880950a0970 R15: ffff8880950a0968
FS:  00007f0a93ff8700(0000) GS:ffff8880aef00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000020 CR3: 00000000a5d39000 CR4: 00000000001426e0
Call Trace:
 sdr_cap_stop_streaming+0x1fc/0x320 drivers/media/platform/vivid/vivid-sdr-cap.c:313
 __vb2_queue_cancel+0xa6/0x8a0 drivers/media/v4l2-core/videobuf2-core.c:1655
 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
 v4l2_release+0xfb/0x190 drivers/media/v4l2-core/v4l2-dev.c:446
 __fput+0x277/0x7a0 fs/file_table.c:210
 ____fput+0x16/0x20 fs/file_table.c:244
 task_work_run+0x119/0x190 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:163
 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:267 [inline]
 do_syscall_64+0x4a9/0x630 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x458da9
RSP: 002b:00007f0a93ff7c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000000458da9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 000000000073bfa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f0a93ff86d4
R13: 00000000004f6e92 R14: 00000000004d01b8 R15: 00000000ffffffff
Code: 00 65 8b 1d b7 14 c3 7e 83 fb 3f 0f 87 63 04 00 00 e8 19 9d 1e 00 89 db 48 0f a3 1d 0f 7a e6 06 0f 82 4c 03 00 00 e8 04 9d 1e 00 <f0> 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: ffff888057ed7b88
RIP: kthread_stop+0x4c/0x650 kernel/kthread.c:525 RSP: ffff888057ed7b88
CR2: 0000000000000020
kobject: 'loop3' (ffff8880a49da0a0): kobject_uevent_env
kobject: 'loop3' (ffff8880a49da0a0): fill_kobj_path: path = '/devices/virtual/block/loop3'
kobject: 'loop5' (ffff8880a4aa41a0): kobject_uevent_env
kobject: 'loop5' (ffff8880a4aa41a0): fill_kobj_path: path = '/devices/virtual/block/loop5'
kobject: 'kvm' (ffff888219f87610): kobject_uevent_env
kobject: 'kvm' (ffff888219f87610): fill_kobj_path: path = '/devices/virtual/misc/kvm'
kobject: 'kvm' (ffff888219f87610): kobject_uevent_env
kobject: 'loop3' (ffff8880a49da0a0): kobject_uevent_env
kobject: 'loop3' (ffff8880a49da0a0): fill_kobj_path: path = '/devices/virtual/block/loop3'
kobject: 'kvm' (ffff888219f87610): fill_kobj_path: path = '/devices/virtual/misc/kvm'
kobject: 'kvm' (ffff888219f87610): kobject_uevent_env
kobject: 'kvm' (ffff888219f87610): fill_kobj_path: path = '/devices/virtual/misc/kvm'
kobject: 'loop2' (ffff8880a49a97e0): kobject_uevent_env
kobject: 'loop2' (ffff8880a49a97e0): fill_kobj_path: path = '/devices/virtual/block/loop2'
audit: type=1400 audit(1557216617.689:40): avc:  denied  { syslog } for  pid=7341 comm="syz-executor.3" capability=34  scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=capability2 permissive=1
kobject: 'loop1' (ffff8880a494f760): kobject_uevent_env
kobject: 'loop1' (ffff8880a494f760): fill_kobj_path: path = '/devices/virtual/block/loop1'
kobject: 'loop5' (ffff8880a4aa41a0): kobject_uevent_env
kobject: 'loop5' (ffff8880a4aa41a0): fill_kobj_path: path = '/devices/virtual/block/loop5'
kobject: 'loop4' (ffff8880a4a2c120): kobject_uevent_env
kobject: 'loop4' (ffff8880a4a2c120): fill_kobj_path: path = '/devices/virtual/block/loop4'
kobject: 'kvm' (ffff888219f87610): kobject_uevent_env
kobject: 'kvm' (ffff888219f87610): kobject_uevent_env
kobject: 'kvm' (ffff888219f87610): fill_kobj_path: path = '/devices/virtual/misc/kvm'
---[ end trace bca887ae9914f60c ]---