kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN
Modules linked in:
CPU: 0 PID: 8479 Comm: syz-executor.2 Not tainted 4.14.112 #2
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff888092b7a440 task.stack: ffff88805fe18000
RIP: 0010:__read_once_size include/linux/compiler.h:183 [inline]
RIP: 0010:atomic_read arch/x86/include/asm/atomic.h:27 [inline]
RIP: 0010:refcount_sub_and_test+0x2b/0xf0 lib/refcount.c:179
RSP: 0018:ffff88805fe1fb98 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffff88809527f5c0 RCX: ffffffff84258400
RDX: 0000000000000004 RSI: 0000000000000020 RDI: 0000000000000001
RBP: ffff88805fe1fbc0 R08: 000000006e92476e R09: ffff888092b7ad08
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000020
R13: 0000000000000001 R14: ffff88809527f5d4 R15: 0000000000000000
FS:  0000000001b1f940(0000) GS:ffff8880aee00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3d84788518 CR3: 0000000084291000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 refcount_dec_and_test+0x1b/0x20 lib/refcount.c:212
 vb2_vmalloc_put+0x18/0x70 drivers/media/v4l2-core/videobuf2-vmalloc.c:68
 __vb2_buf_mem_free+0x106/0x1e0 drivers/media/v4l2-core/videobuf2-core.c:240
 __vb2_free_mem drivers/media/v4l2-core/videobuf2-core.c:409 [inline]
 __vb2_queue_free+0x63a/0x7e0 drivers/media/v4l2-core/videobuf2-core.c:454
 vb2_core_queue_release+0x64/0x80 drivers/media/v4l2-core/videobuf2-core.c:2043
 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: 0033:0x4129e1
RSP: 002b:00007fffcd77c3e0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000004 RCX: 00000000004129e1
RDX: 0000001b32220000 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 0000000000740868 R08: 0000000015c23545 R09: 0000000015c23549
R10: 00007fffcd77c4b0 R11: 0000000000000293 R12: 0000000000000001
R13: 0000000000035b87 R14: 0000000000035bb4 R15: 000000000073bf0c
Code: 55 48 89 e5 41 56 41 55 41 89 fd 41 54 49 89 f4 53 48 83 ec 08 e8 d6 e0 85 fe 4c 89 e2 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 <0f> b6 14 02 4c 89 e0 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 
RIP: __read_once_size include/linux/compiler.h:183 [inline] RSP: ffff88805fe1fb98
RIP: atomic_read arch/x86/include/asm/atomic.h:27 [inline] RSP: ffff88805fe1fb98
RIP: refcount_sub_and_test+0x2b/0xf0 lib/refcount.c:179 RSP: ffff88805fe1fb98
kobject: 'loop0' (ffff8880a490a560): kobject_uevent_env
kobject: 'loop0' (ffff8880a490a560): fill_kobj_path: path = '/devices/virtual/block/loop0'
---[ end trace c4473eca368f53d5 ]---