IPVS: length: 159 != 8
FAULT_INJECTION: forcing a failure.
name failslab, interval 1, probability 0, space 0, times 0
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 961e7067 P4D 961e7067 PUD 9f3b2067 PMD 0 
CPU: 0 PID: 24582 Comm: syz-executor.1 Not tainted 4.14.111 #1
Oops: 0002 [#1] PREEMPT SMP KASAN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Modules linked in:
Call Trace:
CPU: 1 PID: 24585 Comm: syz-executor.3 Not tainted 4.14.111 #1
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x138/0x19c lib/dump_stack.c:53
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 fail_dump lib/fault-inject.c:51 [inline]
 should_fail.cold+0x10f/0x159 lib/fault-inject.c:149
task: ffff8880a969c540 task.stack: ffff888097188000
 should_failslab+0xdb/0x130 mm/failslab.c:32
RIP: 0010:atomic_inc arch/x86/include/asm/atomic.h:92 [inline]
RIP: 0010:kthread_stop+0x4c/0x650 kernel/kthread.c:525
 slab_pre_alloc_hook mm/slab.h:421 [inline]
 slab_alloc mm/slab.c:3376 [inline]
 kmem_cache_alloc_trace+0x2ec/0x790 mm/slab.c:3616
RSP: 0018:ffff88809718f760 EFLAGS: 00010297
RAX: ffff8880a969c540 RBX: 0000000000000001 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 00000000ffffffff RDI: 0000000000000282
RBP: ffff88809718f780 R08: ffff8880a969c540 R09: 0000000000000000
 kmalloc include/linux/slab.h:488 [inline]
 sock_alloc_inode+0x63/0x260 net/socket.c:254
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
 alloc_inode+0x66/0x190 fs/inode.c:209
R13: ffff8880981ab4f0 R14: ffff8880981ab4e8 R15: ffffffff89bb8ac0
 new_inode_pseudo+0x19/0xf0 fs/inode.c:891
FS:  00007f1333f3a700(0000) GS:ffff8880aef00000(0000) knlGS:0000000000000000
 sock_alloc+0x41/0x280 net/socket.c:569
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 SYSC_accept4+0xcd/0x640 net/socket.c:1556
CR2: 0000000000000020 CR3: 0000000090dc0000 CR4: 00000000001406e0
Call Trace:
 vivid_stop_generating_vid_cap+0x1b9/0x664 drivers/media/platform/vivid/vivid-kthread-cap.c:934
 vid_cap_stop_streaming+0x7c/0xd0 drivers/media/platform/vivid/vivid-vid-cap.c:273
 SyS_accept4+0x2c/0x40 net/socket.c:1537
 __vb2_queue_cancel+0xa6/0x8a0 drivers/media/v4l2-core/videobuf2-core.c:1655
 do_syscall_64+0x1eb/0x630 arch/x86/entry/common.c:289
 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
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
 vb2_core_queue_release+0x1d/0x80 drivers/media/v4l2-core/videobuf2-core.c:2040
RIP: 0033:0x458c29
 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
RSP: 002b:00007f7ee0e25c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000120
 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
RAX: ffffffffffffffda RBX: 00007f7ee0e25c90 RCX: 0000000000458c29
RDX: 00000000200003c0 RSI: 0000000020000380 RDI: 0000000000000006
RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000080000 R11: 0000000000000246 R12: 00007f7ee0e266d4
R13: 00000000004beabc R14: 00000000004cf7f8 R15: 0000000000000005
 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
 exit_task_work include/linux/task_work.h:22 [inline]
 do_exit+0x7df/0x2c10 kernel/exit.c:874
 do_group_exit+0x111/0x330 kernel/exit.c:977
 get_signal+0x348/0x1a80 kernel/signal.c:2407
 do_signal+0x86/0x1980 arch/x86/kernel/signal.c:809
kobject: 'loop2' (ffff8880a4a25220): kobject_uevent_env
 exit_to_usermode_loop+0x15c/0x220 arch/x86/entry/common.c:159
 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
kobject: 'loop2' (ffff8880a4a25220): fill_kobj_path: path = '/devices/virtual/block/loop2'
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x458c29
RSP: 002b:00007f1333f39cf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: 0000000000000001 RBX: 000000000073bf08 RCX: 0000000000458c29
RDX: 00000000004ca570 RSI: 0000000000000081 RDI: 000000000073bf0c
RBP: 000000000073bf00 R08: 0000000000000009 R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 000000000073bf0c
R13: 00007ffe31b7c5bf R14: 00007f1333f3a9c0 R15: 000000000073bf0c
Code: 00 65 
==================================================================
8b 
BUG: KASAN: use-after-free in __vb2_perform_fileio+0xddf/0xeb0 drivers/media/v4l2-core/videobuf2-core.c:2379
1d 
Read of size 4 at addr ffff88807854f0dc by task syz-executor.4/24583
67 

3f 
CPU: 0 PID: 24583 Comm: syz-executor.4 Not tainted 4.14.111 #1
c3 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
7e 
Call Trace:
83 
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x138/0x19c lib/dump_stack.c:53
fb 
3f 
 print_address_description.cold+0x7c/0x1dc mm/kasan/report.c:252
0f 
87 
 kasan_report_error mm/kasan/report.c:351 [inline]
 kasan_report mm/kasan/report.c:409 [inline]
 kasan_report.cold+0xaf/0x2b5 mm/kasan/report.c:393
63 
 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report.c:429
04 
 __vb2_perform_fileio+0xddf/0xeb0 drivers/media/v4l2-core/videobuf2-core.c:2379
00 
00 
e8 
 vb2_read+0x3b/0x50 drivers/media/v4l2-core/videobuf2-core.c:2490
79 
 vb2_fop_read+0x1f5/0x3e0 drivers/media/v4l2-core/videobuf2-v4l2.c:895
95 
1e 
 v4l2_read+0x1ac/0x210 drivers/media/v4l2-core/v4l2-dev.c:309
00 
 __vfs_read+0x107/0x6b0 fs/read_write.c:411
89 
db 
48 
0f 
a3 
1d 
ff 
96 
e6 
 vfs_read+0x137/0x350 fs/read_write.c:447
06 
 SYSC_read fs/read_write.c:573 [inline]
 SyS_read+0xb8/0x180 fs/read_write.c:566
0f 
82 
4c 
03 
 do_syscall_64+0x1eb/0x630 arch/x86/entry/common.c:289
00 
00 
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
e8 
RIP: 0033:0x458c29
64 
RSP: 002b:00007f8b98d6dc78 EFLAGS: 00000246
95 
 ORIG_RAX: 0000000000000000
1e 
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000458c29
00 
RDX: 000000000000005d RSI: 0000000020001480 RDI: 0000000000000004
<f0> 
RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000
41 
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f8b98d6e6d4
ff 
R13: 00000000004c4935 R14: 00000000004d9f08 R15: 00000000ffffffff
44 

24 
Allocated by task 24583:
20 
 save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59
49 
 save_stack+0x45/0xd0 mm/kasan/kasan.c:447
8d 
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_kmalloc mm/kasan/kasan.c:551 [inline]
 kasan_kmalloc+0xce/0xf0 mm/kasan/kasan.c:529
7c 
 kmem_cache_alloc_trace+0x152/0x790 mm/slab.c:3618
24 
 kmalloc include/linux/slab.h:488 [inline]
 kzalloc include/linux/slab.h:661 [inline]
 __vb2_init_fileio+0x182/0xa90 drivers/media/v4l2-core/videobuf2-core.c:2224
24 
 __vb2_perform_fileio+0x9f0/0xeb0 drivers/media/v4l2-core/videobuf2-core.c:2358
48 
 vb2_read+0x3b/0x50 drivers/media/v4l2-core/videobuf2-core.c:2490
b8 
 vb2_fop_read+0x1f5/0x3e0 drivers/media/v4l2-core/videobuf2-v4l2.c:895
00 
 v4l2_read+0x1ac/0x210 drivers/media/v4l2-core/v4l2-dev.c:309
00 
 __vfs_read+0x107/0x6b0 fs/read_write.c:411
00 
 vfs_read+0x137/0x350 fs/read_write.c:447
00 
 SYSC_read fs/read_write.c:573 [inline]
 SyS_read+0xb8/0x180 fs/read_write.c:566
00 
 do_syscall_64+0x1eb/0x630 arch/x86/entry/common.c:289
fc 
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
ff 

df 
Freed by task 24576:
 save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59
RIP: atomic_inc arch/x86/include/asm/atomic.h:92 [inline] RSP: ffff88809718f760
RIP: kthread_stop+0x4c/0x650 kernel/kthread.c:525 RSP: ffff88809718f760
 save_stack+0x45/0xd0 mm/kasan/kasan.c:447
CR2: 0000000000000020
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_slab_free+0x75/0xc0 mm/kasan/kasan.c:524
---[ end trace fea1de067bde83b0 ]---
 __cache_free mm/slab.c:3496 [inline]
 kfree+0xcc/0x270 mm/slab.c:3815