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BUG: KASAN: slab-out-of-bounds in cap_convert_nscap+0x501/0x610 security/commoncap.c:498
Read of size 4 at addr ffff8801d4567b00 by task syz-executor1/21668

CPU: 0 PID: 21668 Comm: syz-executor1 Not tainted 4.15.0-rc4-next-20171221+ #78
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:252
 kasan_report_error mm/kasan/report.c:351 [inline]
 kasan_report+0x25b/0x340 mm/kasan/report.c:409
 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report.c:429
 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: 0033:0x452ac9
RSP: 002b:00007f612a74dc58 EFLAGS: 00000212 ORIG_RAX: 00000000000000be
RAX: ffffffffffffffda RBX: 000000000071bea0 RCX: 0000000000452ac9
RDX: 000000002073bffd RSI: 0000000020c11fec RDI: 0000000000000014
RBP: 0000000000000556 R08: 0000000000000002 R09: 0000000000000000
R10: 0000000000000003 R11: 0000000000000212 R12: 00000000006f60b0
R13: 00000000ffffffff R14: 00007f612a74e6d4 R15: 0000000000000000

Allocated by task 21668:
 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:3673 [inline]
 __kmalloc_node+0x47/0x70 mm/slab.c:3680
 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 3395:
 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:3489 [inline]
 kfree+0xd6/0x260 mm/slab.c:3804
 netlbl_secattr_destroy include/net/netlabel.h:378 [inline]
 netlbl_secattr_free include/net/netlabel.h:409 [inline]
 selinux_netlbl_sk_security_free+0x218/0x2f0 security/selinux/netlabel.c:170
 selinux_sk_free_security+0x47/0x60 security/selinux/hooks.c:4908
 security_sk_free+0x48/0x80 security/security.c:1431
 sk_prot_free net/core/sock.c:1504 [inline]
 __sk_destruct+0x609/0x910 net/core/sock.c:1590
 __rcu_reclaim kernel/rcu/rcu.h:172 [inline]
 rcu_do_batch kernel/rcu/tree.c:2675 [inline]
 invoke_rcu_callbacks kernel/rcu/tree.c:2934 [inline]
 __rcu_process_callbacks kernel/rcu/tree.c:2901 [inline]
 rcu_process_callbacks+0xd6c/0x17f0 kernel/rcu/tree.c:2918
 __do_softirq+0x2d7/0xb85 kernel/softirq.c:285

The buggy address belongs to the object at ffff8801d4567b00
 which belongs to the cache kmalloc-32 of size 32
The buggy address is located 0 bytes inside of
 32-byte region [ffff8801d4567b00, ffff8801d4567b20)
The buggy address belongs to the page:
page:00000000b05d3153 count:1 mapcount:0 mapping:000000009051da2c index:0xffff8801d4567fc1
flags: 0x2fffc0000000100(slab)
raw: 02fffc0000000100 ffff8801d4567000 ffff8801d4567fc1 000000010000003f
raw: ffffea000751f660 ffffea000751f920 ffff8801dac001c0 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801d4567a00: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
 ffff8801d4567a80: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
>ffff8801d4567b00: 03 fc fc fc fc fc fc fc fb fb fb fb fc fc fc fc
                   ^
 ffff8801d4567b80: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
 ffff8801d4567c00: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
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