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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 ffff8801d5325540 by task syz-executor2/27013

CPU: 1 PID: 27013 Comm: syz-executor2 Not tainted 4.15.0-rc5+ #243
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:00007fdfd165ec58 EFLAGS: 00000212 ORIG_RAX: 00000000000000be
RAX: ffffffffffffffda RBX: 000000000071bea0 RCX: 0000000000452ac9
RDX: 00000000206dcfff RSI: 0000000020590000 RDI: 0000000000000015
RBP: 000000000000033b R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000212 R12: 00000000006f2e28
R13: 00000000ffffffff R14: 00007fdfd165f6d4 R15: 0000000000000000

Allocated by task 27013:
 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:3672 [inline]
 __kmalloc_node+0x47/0x70 mm/slab.c:3679
 kmalloc_node include/linux/slab.h:541 [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 3412:
 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:3488 [inline]
 kfree+0xd6/0x260 mm/slab.c:3803
 simple_xattrs_free include/linux/xattr.h:97 [inline]
 shmem_evict_inode+0x1b0/0xb30 mm/shmem.c:1083
 evict+0x481/0x920 fs/inode.c:553
 iput_final fs/inode.c:1515 [inline]
 iput+0x7b9/0xaf0 fs/inode.c:1542
 dentry_unlink_inode+0x4b0/0x5e0 fs/dcache.c:375
 d_delete+0x1a7/0x250 fs/dcache.c:2367
 vfs_rmdir+0x32d/0x410 fs/namei.c:3871
 do_rmdir+0x4c8/0x5f0 fs/namei.c:3919
 SYSC_rmdir fs/namei.c:3937 [inline]
 SyS_rmdir+0x1a/0x20 fs/namei.c:3935
 entry_SYSCALL_64_fastpath+0x1f/0x96

The buggy address belongs to the object at ffff8801d5325540
 which belongs to the cache kmalloc-32 of size 32
The buggy address is located 0 bytes inside of
 32-byte region [ffff8801d5325540, ffff8801d5325560)
The buggy address belongs to the page:
page:000000001f88e10e count:1 mapcount:0 mapping:00000000e540f4bc index:0xffff8801d5325fc1
flags: 0x2fffc0000000100(slab)
raw: 02fffc0000000100 ffff8801d5325000 ffff8801d5325fc1 000000010000003c
raw: ffffea00071c02e0 ffffea00075431a0 ffff8801dac001c0 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801d5325400: 00 00 fc fc fc fc fc fc fb fb fb fb fc fc fc fc
 ffff8801d5325480: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
>ffff8801d5325500: fb fb fb fb fc fc fc fc 01 fc fc fc fc fc fc fc
                                           ^
 ffff8801d5325580: 00 00 00 fc fc fc fc fc fb fb fb fb fc fc fc fc
 ffff8801d5325600: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
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