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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 ffff8801be60a640 by task syz-executor6/7061

CPU: 1 PID: 7061 Comm: syz-executor6 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: 0033:0x452ac9
RSP: 002b:00007ff5f38dfc58 EFLAGS: 00000212 ORIG_RAX: 00000000000000be
RAX: ffffffffffffffda RBX: 000000000071bea0 RCX: 0000000000452ac9
RDX: 0000000020003fff RSI: 0000000020008000 RDI: 0000000000000013
RBP: 00000000000003a3 R08: 0000000000000003 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000212 R12: 00000000006f37e8
R13: 00000000ffffffff R14: 00007ff5f38e06d4 R15: 0000000000000000

Allocated by task 7061:
 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 3796:
 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
 selinux_cred_free+0x48/0x70 security/selinux/hooks.c:3815
 security_cred_free+0x48/0x80 security/security.c:995
 put_cred_rcu+0x106/0x400 kernel/cred.c:117
 __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 ffff8801be60a640
 which belongs to the cache kmalloc-32 of size 32
The buggy address is located 0 bytes inside of
 32-byte region [ffff8801be60a640, ffff8801be60a660)
The buggy address belongs to the page:
page:ffffea0006f98280 count:1 mapcount:0 mapping:ffff8801be60a000 index:0xffff8801be60afc1
flags: 0x2fffc0000000100(slab)
raw: 02fffc0000000100 ffff8801be60a000 ffff8801be60afc1 000000010000003f
raw: ffffea0006faf520 ffffea0006fae960 ffff8801dac001c0 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801be60a500: fb fb fb fb fc fc fc fc 00 00 00 fc fc fc fc fc
 ffff8801be60a580: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
>ffff8801be60a600: fb fb fb fb fc fc fc fc 01 fc fc fc fc fc fc fc
                                           ^
 ffff8801be60a680: 00 00 01 fc fc fc fc fc fb fb fb fb fc fc fc fc
 ffff8801be60a700: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
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