audit: type=1400 audit(1514540579.225:7): avc:  denied  { map } for  pid=3155 comm="syzkaller097903" path="/root/syzkaller097903112" dev="sda1" ino=16481 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1
==================================================================
BUG: KASAN: slab-out-of-bounds in cap_convert_nscap+0x501/0x610 security/commoncap.c:498
Read of size 4 at addr ffff8801c9283ac0 by task syzkaller097903/3155

CPU: 1 PID: 3155 Comm: syzkaller097903 Not tainted 4.15.0-rc4-mm1+ #49
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:355 [inline]
 kasan_report+0x23b/0x360 mm/kasan/report.c:413
 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report.c:433
 cap_convert_nscap+0x501/0x610 security/commoncap.c:498
 setxattr+0x365/0x400 fs/xattr.c:446
 SYSC_fsetxattr fs/xattr.c:508 [inline]
 SyS_fsetxattr+0x130/0x190 fs/xattr.c:497
 entry_SYSCALL_64_fastpath+0x1f/0x96
RIP: 0033:0x43fcb9
RSP: 002b:00007ffc25686908 EFLAGS: 00000203 ORIG_RAX: 00000000000000be
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 000000000043fcb9
RDX: 00000000209b8000 RSI: 0000000020d4bfe8 RDI: 0000000000000003
RBP: 00000000006ca018 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000203 R12: 0000000000401620
R13: 00000000004016b0 R14: 0000000000000000 R15: 0000000000000000

Allocated by task 3155:
 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:551
 __do_kmalloc_node mm/slab.c:3669 [inline]
 __kmalloc_node+0x47/0x70 mm/slab.c:3676
 kmalloc_node include/linux/slab.h:558 [inline]
 kvmalloc_node+0x99/0xd0 mm/util.c:397
 kvmalloc include/linux/mm.h:541 [inline]
 setxattr+0x152/0x400 fs/xattr.c:435
 SYSC_fsetxattr fs/xattr.c:508 [inline]
 SyS_fsetxattr+0x130/0x190 fs/xattr.c:497
 entry_SYSCALL_64_fastpath+0x1f/0x96

Freed by task 1649:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_slab_free+0x71/0xc0 mm/kasan/kasan.c:524
 __cache_free mm/slab.c:3485 [inline]
 kfree+0xd6/0x260 mm/slab.c:3800
 security_inode_init_security+0x1c3/0x390 security/security.c:494
 shmem_mknod+0x9b/0x1b0 mm/shmem.c:3012
 shmem_mkdir+0x29/0x50 mm/shmem.c:3058
 vfs_mkdir+0x390/0x600 fs/namei.c:3818
 SYSC_mkdirat fs/namei.c:3841 [inline]
 SyS_mkdirat fs/namei.c:3825 [inline]
 SYSC_mkdir fs/namei.c:3852 [inline]
 SyS_mkdir+0x220/0x2a0 fs/namei.c:3850
 entry_SYSCALL_64_fastpath+0x1f/0x96

The buggy address belongs to the object at ffff8801c9283ac0
 which belongs to the cache kmalloc-32 of size 32
The buggy address is located 0 bytes inside of
 32-byte region [ffff8801c9283ac0, ffff8801c9283ae0)
The buggy address belongs to the page:
page:ffffea000724a0c0 count:1 mapcount:0 mapping:ffff8801c9283000 index:0xffff8801c9283fc1
flags: 0x2fffc0000000100(slab)
raw: 02fffc0000000100 ffff8801c9283000 ffff8801c9283fc1 000000010000003f
raw: ffffea000726c220 ffffea0007261c20 ffff8801dac001c0 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801c9283980: 00 00 00 fc fc fc fc fc 05 fc fc fc fc fc fc fc
 ffff8801c9283a00: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
>ffff8801c9283a80: fb fb fb fb fc fc fc fc 01 fc fc fc fc fc fc fc
                                           ^
 ffff8801c9283b00: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
 ffff8801c9283b80: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
==================================================================