audit: type=1326 audit(1550625187.754:31): auid=4294967295 uid=0 gid=0 ses=4294967295 subj==unconfined pid=8790 comm="syz-executor.0" exe="/root/syz-executor.0" sig=31 arch=c000003e syscall=228 compat=0 ip=0x45ac8a code=0x0
==================================================================
BUG: KASAN: use-after-free in __lock_acquire+0x30e0/0x4700 kernel/locking/lockdep.c:3215
Read of size 8 at addr ffff88809a99c580 by task syz-executor.0/8790

CPU: 1 PID: 8790 Comm: syz-executor.0 Not tainted 5.0.0-rc7+ #79
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+0x172/0x1f0 lib/dump_stack.c:113
 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:187
 kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317
 __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:135
 __lock_acquire+0x30e0/0x4700 kernel/locking/lockdep.c:3215
 lock_acquire+0x16f/0x3f0 kernel/locking/lockdep.c:3841
 __mutex_lock_common kernel/locking/mutex.c:925 [inline]
 __mutex_lock+0xf7/0x1310 kernel/locking/mutex.c:1072
 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087
 seccomp_notify_release+0x62/0x280 kernel/seccomp.c:982
 __fput+0x2df/0x8d0 fs/file_table.c:278
 ____fput+0x16/0x20 fs/file_table.c:309
 task_work_run+0x14a/0x1c0 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_usermode_loop+0x273/0x2c0 arch/x86/entry/common.c:166
 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:268 [inline]
 do_syscall_64+0x52d/0x610 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x411d31
Code: 75 14 b8 03 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 94 19 00 00 c3 48 83 ec 08 e8 0a fc ff ff 48 89 04 24 b8 03 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 53 fc ff ff 48 89 d0 48 83 c4 08 48 3d 01
RSP: 002b:0000000000a4fd90 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000005 RCX: 0000000000411d31
RDX: 0000000000000000 RSI: 00000000007402a8 RDI: 0000000000000004
RBP: 0000000000000000 R08: 00000000007402a0 R09: 0000000000013474
R10: 0000000000a4fcb0 R11: 0000000000000293 R12: 0000000000000000
R13: 0000000000000001 R14: 000000000000002e R15: 0000000000000000

Allocated by task 8791:
 save_stack+0x45/0xd0 mm/kasan/common.c:73
 set_track mm/kasan/common.c:85 [inline]
 __kasan_kmalloc mm/kasan/common.c:496 [inline]
 __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:469
 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:504
 kmem_cache_alloc_trace+0x151/0x760 mm/slab.c:3609
 kmalloc include/linux/slab.h:545 [inline]
 kzalloc include/linux/slab.h:740 [inline]
 seccomp_prepare_filter kernel/seccomp.c:451 [inline]
 seccomp_prepare_user_filter kernel/seccomp.c:491 [inline]
 seccomp_set_mode_filter kernel/seccomp.c:1260 [inline]
 do_seccomp+0x73e/0x2250 kernel/seccomp.c:1374
 __do_sys_seccomp kernel/seccomp.c:1393 [inline]
 __se_sys_seccomp kernel/seccomp.c:1390 [inline]
 __x64_sys_seccomp+0x73/0xb0 kernel/seccomp.c:1390
 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 8791:
 save_stack+0x45/0xd0 mm/kasan/common.c:73
kobject: 'queues' (00000000dd2ac444): kobject_uevent_env
 set_track mm/kasan/common.c:85 [inline]
 __kasan_slab_free+0x102/0x150 mm/kasan/common.c:458
 kasan_slab_free+0xe/0x10 mm/kasan/common.c:466
 __cache_free mm/slab.c:3487 [inline]
 kfree+0xcf/0x230 mm/slab.c:3806
 seccomp_filter_free kernel/seccomp.c:565 [inline]
 seccomp_filter_free kernel/seccomp.c:561 [inline]
 seccomp_set_mode_filter kernel/seccomp.c:1315 [inline]
 do_seccomp+0xafb/0x2250 kernel/seccomp.c:1374
 __do_sys_seccomp kernel/seccomp.c:1393 [inline]
 __se_sys_seccomp kernel/seccomp.c:1390 [inline]
 __x64_sys_seccomp+0x73/0xb0 kernel/seccomp.c:1390
 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
kobject: 'queues' (00000000dd2ac444): kobject_uevent_env: filter function caused the event to drop!
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff88809a99c500
 which belongs to the cache kmalloc-192 of size 192
The buggy address is located 128 bytes inside of
 192-byte region [ffff88809a99c500, ffff88809a99c5c0)
The buggy address belongs to the page:
page:ffffea00026a6700 count:1 mapcount:0 mapping:ffff88812c3f0040 index:0x0
flags: 0x1fffc0000000200(slab)
kobject: 'rx-0' (00000000dbc1a00b): kobject_add_internal: parent: 'queues', set: 'queues'
raw: 01fffc0000000200 ffffea00026ad808 ffffea0002683308 ffff88812c3f0040
raw: 0000000000000000 ffff88809a99c000 0000000100000010 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88809a99c480: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc
 ffff88809a99c500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
kobject: 'rx-0' (00000000dbc1a00b): kobject_uevent_env
>ffff88809a99c580: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
                   ^
 ffff88809a99c600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88809a99c680: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
==================================================================