==================================================================
BUG: KASAN: slab-out-of-bounds in cap_convert_nscap+0x501/0x610 security/commoncap.c:498
Read of size 4 at addr ffff8801d8a04d40 by task syz-executor7/30017

CPU: 1 PID: 30017 Comm: syz-executor7 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:00007fdc5548dc58 EFLAGS: 00000212 ORIG_RAX: 00000000000000be
RAX: ffffffffffffffda RBX: 000000000071bea0 RCX: 0000000000452ac9
RDX: 00000000202dc000 RSI: 0000000020673000 RDI: 0000000000000013
RBP: 00000000000003a3 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000212 R12: 00000000006f37e8
R13: 00000000ffffffff R14: 00007fdc5548e6d4 R15: 0000000000000000

Allocated by task 30017:
 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 1606:
 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
 simple_xattrs_free include/linux/xattr.h:97 [inline]
 shmem_evict_inode+0x1b0/0xb30 mm/shmem.c:1083
 evict+0x481/0x920 fs/inode.c:552
 iput_final fs/inode.c:1514 [inline]
 iput+0x7b9/0xaf0 fs/inode.c:1541
 dentry_unlink_inode+0x4b0/0x5e0 fs/dcache.c:375
 __dentry_kill+0x3b7/0x6d0 fs/dcache.c:572
 dentry_kill fs/dcache.c:613 [inline]
 dput.part.23+0x5a0/0x830 fs/dcache.c:823
 dput+0x1f/0x30 fs/dcache.c:787
 SYSC_renameat2 fs/namei.c:4615 [inline]
 SyS_renameat2 fs/namei.c:4500 [inline]
 SYSC_rename fs/namei.c:4651 [inline]
 SyS_rename+0x909/0xc90 fs/namei.c:4649
 entry_SYSCALL_64_fastpath+0x1f/0x96

The buggy address belongs to the object at ffff8801d8a04d40
 which belongs to the cache kmalloc-32 of size 32
The buggy address is located 0 bytes inside of
 32-byte region [ffff8801d8a04d40, ffff8801d8a04d60)
The buggy address belongs to the page:
page:ffffea0007628100 count:1 mapcount:0 mapping:ffff8801d8a04000 index:0xffff8801d8a04fc1
flags: 0x2fffc0000000100(slab)
raw: 02fffc0000000100 ffff8801d8a04000 ffff8801d8a04fc1 0000000100000036
raw: ffffea0007664a60 ffffea0007530e60 ffff8801dac001c0 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801d8a04c00: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
 ffff8801d8a04c80: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
>ffff8801d8a04d00: fb fb fb fb fc fc fc fc 01 fc fc fc fc fc fc fc
                                           ^
 ffff8801d8a04d80: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
 ffff8801d8a04e00: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
==================================================================