audit: type=1326 audit(1551087215.859:55): auid=4294967295 uid=0 gid=0 ses=4294967295 subj==unconfined pid=31658 comm="syz-executor.5" exe="/root/syz-executor.5" sig=31 arch=40000003 syscall=265 compat=1 ip=0xf7f7b869 code=0x0
==================================================================
BUG: KASAN: use-after-free in __lock_acquire+0x30e0/0x4700 kernel/locking/lockdep.c:3215
Read of size 8 at addr ffff88809dbbd280 by task syz-executor.5/31659

CPU: 0 PID: 31659 Comm: syz-executor.5 Not tainted 5.0.0-rc8 #88
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
 exit_task_work include/linux/task_work.h:22 [inline]
 do_exit+0x92c/0x2fd0 kernel/exit.c:875
 do_group_exit+0x135/0x370 kernel/exit.c:979
 get_signal+0x399/0x1d50 kernel/signal.c:2575
 do_signal+0x87/0x1940 arch/x86/kernel/signal.c:816
 exit_to_usermode_loop+0x244/0x2c0 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_32_irqs_on arch/x86/entry/common.c:341 [inline]
 do_fast_syscall_32+0xa9d/0xc98 arch/x86/entry/common.c:397
 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139
RIP: 0023:0xf7f7b869
Code: Bad RIP value.
RSP: 002b:00000000f5d7712c EFLAGS: 00000292 ORIG_RAX: 00000000000000f0
RAX: fffffffffffffe00 RBX: 000000000814af68 RCX: 0000000000000080
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000000814af6c
RBP: 00000000f5d77228 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000

Allocated by task 31659:
 save_stack+0x45/0xd0 mm/kasan/common.c:73
 set_track mm/kasan/common.c:85 [inline]
 __kasan_kmalloc mm/kasan/common.c:495 [inline]
 __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:468
 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:509
 kmem_cache_alloc_trace+0x151/0x760 mm/slab.c:3615
 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]
 __ia32_sys_seccomp+0x72/0xb0 kernel/seccomp.c:1390
 do_syscall_32_irqs_on arch/x86/entry/common.c:326 [inline]
 do_fast_syscall_32+0x281/0xc98 arch/x86/entry/common.c:397
 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139

Freed by task 31659:
 save_stack+0x45/0xd0 mm/kasan/common.c:73
 set_track mm/kasan/common.c:85 [inline]
 __kasan_slab_free+0x102/0x150 mm/kasan/common.c:457
 kasan_slab_free+0xe/0x10 mm/kasan/common.c:465
 __cache_free mm/slab.c:3494 [inline]
 kfree+0xcf/0x230 mm/slab.c:3811
 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]
 __ia32_sys_seccomp+0x72/0xb0 kernel/seccomp.c:1390
 do_syscall_32_irqs_on arch/x86/entry/common.c:326 [inline]
 do_fast_syscall_32+0x281/0xc98 arch/x86/entry/common.c:397
 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139

The buggy address belongs to the object at ffff88809dbbd200
 which belongs to the cache kmalloc-192 of size 192
The buggy address is located 128 bytes inside of
 192-byte region [ffff88809dbbd200, ffff88809dbbd2c0)
The buggy address belongs to the page:
page:ffffea000276ef40 count:1 mapcount:0 mapping:ffff88812c3f0040 index:0xffff88809dbbda00
flags: 0x1fffc0000000200(slab)
raw: 01fffc0000000200 ffffea00029e1e48 ffffea00023896c8 ffff88812c3f0040
raw: ffff88809dbbda00 ffff88809dbbd000 000000010000000a 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88809dbbd180: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
 ffff88809dbbd200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88809dbbd280: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
                   ^
 ffff88809dbbd300: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88809dbbd380: 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================