audit: type=1400 audit(1515680378.393:8): avc:  denied  { sys_admin } for  pid=3508 comm="syzkaller203412" capability=21  scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=cap_userns permissive=1
audit: type=1400 audit(1515680378.446:9): avc:  denied  { sys_chroot } for  pid=3509 comm="syzkaller203412" capability=18  scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=cap_userns permissive=1
==================================================================
BUG: KASAN: use-after-free in memcpy include/linux/string.h:344 [inline]
BUG: KASAN: use-after-free in array_map_update_elem+0x197/0x240 kernel/bpf/arraymap.c:249
Write of size 1 at addr ffff8801cb125bc0 by task syzkaller203412/3509

CPU: 1 PID: 3509 Comm: syzkaller203412 Not tainted 4.15.0-rc7-next-20180111+ #94
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x194/0x257 lib/dump_stack.c:53
 print_address_description+0x73/0x250 mm/kasan/report.c:256
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report+0x23b/0x360 mm/kasan/report.c:412
 check_memory_region_inline mm/kasan/kasan.c:260 [inline]
 check_memory_region+0x137/0x190 mm/kasan/kasan.c:267
 memcpy+0x37/0x50 mm/kasan/kasan.c:303
 memcpy include/linux/string.h:344 [inline]
 array_map_update_elem+0x197/0x240 kernel/bpf/arraymap.c:249
 map_update_elem kernel/bpf/syscall.c:687 [inline]
 SYSC_bpf kernel/bpf/syscall.c:1811 [inline]
 SyS_bpf+0x32df/0x4400 kernel/bpf/syscall.c:1782
 entry_SYSCALL_64_fastpath+0x29/0xa0
RIP: 0033:0x440ac9
RSP: 002b:00000000007dff68 EFLAGS: 00000203 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007ffe6a583b10 RCX: 0000000000440ac9
RDX: 0000000000000020 RSI: 0000000020eaf000 RDI: 0000000000000002
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000203 R12: 00000000004022a0
R13: 0000000000402330 R14: 0000000000000000 R15: 0000000000000000

Allocated by task 3071:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:552
 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:489
 kmem_cache_alloc+0x12e/0x760 mm/slab.c:3541
 getname_flags+0xcb/0x580 fs/namei.c:138
 user_path_at_empty+0x2d/0x50 fs/namei.c:2587
 user_path_at include/linux/namei.h:57 [inline]
 SYSC_faccessat fs/open.c:384 [inline]
 SyS_faccessat fs/open.c:353 [inline]
 SYSC_access fs/open.c:431 [inline]
 SyS_access+0x22c/0x6a0 fs/open.c:429
 entry_SYSCALL_64_fastpath+0x29/0xa0

Freed by task 3071:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 __kasan_slab_free+0x11a/0x170 mm/kasan/kasan.c:520
 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:527
 __cache_free mm/slab.c:3485 [inline]
 kmem_cache_free+0x86/0x2b0 mm/slab.c:3743
 putname+0xee/0x130 fs/namei.c:258
 filename_lookup+0x315/0x500 fs/namei.c:2342
 user_path_at_empty+0x40/0x50 fs/namei.c:2587
 user_path_at include/linux/namei.h:57 [inline]
 SYSC_faccessat fs/open.c:384 [inline]
 SyS_faccessat fs/open.c:353 [inline]
 SYSC_access fs/open.c:431 [inline]
 SyS_access+0x22c/0x6a0 fs/open.c:429
 entry_SYSCALL_64_fastpath+0x29/0xa0

The buggy address belongs to the object at ffff8801cb124e40
 which belongs to the cache names_cache of size 4096
The buggy address is located 3456 bytes inside of
 4096-byte region [ffff8801cb124e40, ffff8801cb125e40)
The buggy address belongs to the page:
page:ffffea00072c4900 count:1 mapcount:0 mapping:ffff8801cb124e40 index:0x0 compound_mapcount: 0
flags: 0x2fffc0000008100(slab|head)
raw: 02fffc0000008100 ffff8801cb124e40 0000000000000000 0000000100000001
raw: ffffea000729bc20 ffffea000729bca0 ffff8801dae30600 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801cb125a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8801cb125b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8801cb125b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                           ^
 ffff8801cb125c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8801cb125c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================