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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 ffff8801d1423540 by task syz-executor4/8212

CPU: 0 PID: 8212 Comm: syz-executor4 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
 path_setxattr+0x198/0x1e0 fs/xattr.c:472
 SYSC_setxattr fs/xattr.c:487 [inline]
 SyS_setxattr+0x3b/0x50 fs/xattr.c:483
 entry_SYSCALL_64_fastpath+0x1f/0x96
RIP: 0033:0x452ac9
RSP: 002b:00007f7188071c58 EFLAGS: 00000212 ORIG_RAX: 00000000000000bc
RAX: ffffffffffffffda RBX: 000000000071bea0 RCX: 0000000000452ac9
RDX: 0000000020992ffd RSI: 0000000020a88ff4 RDI: 00000000205e3000
RBP: 00000000000003a3 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000003 R11: 0000000000000212 R12: 00000000006f37e8
R13: 00000000ffffffff R14: 00007f71880726d4 R15: 0000000000000000

Allocated by task 8212:
 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
 path_setxattr+0x198/0x1e0 fs/xattr.c:472
 SYSC_setxattr fs/xattr.c:487 [inline]
 SyS_setxattr+0x3b/0x50 fs/xattr.c:483
 entry_SYSCALL_64_fastpath+0x1f/0x96

Freed by task 3174:
 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
 kvfree+0x36/0x60 mm/util.c:416
 setxattr+0x1f5/0x400 fs/xattr.c:455
 path_setxattr+0x198/0x1e0 fs/xattr.c:472
 SYSC_lsetxattr fs/xattr.c:494 [inline]
 SyS_lsetxattr+0x38/0x50 fs/xattr.c:490
 entry_SYSCALL_64_fastpath+0x1f/0x96

The buggy address belongs to the object at ffff8801d1423540
 which belongs to the cache kmalloc-32 of size 32
The buggy address is located 0 bytes inside of
 32-byte region [ffff8801d1423540, ffff8801d1423560)
The buggy address belongs to the page:
page:00000000a8c14750 count:1 mapcount:0 mapping:000000002d325277 index:0xffff8801d1423fc1
flags: 0x2fffc0000000100(slab)
raw: 02fffc0000000100 ffff8801d1423000 ffff8801d1423fc1 000000010000003e
raw: ffffea0007433360 ffffea000748a760 ffff8801dac001c0 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801d1423400: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
 ffff8801d1423480: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
>ffff8801d1423500: fb fb fb fb fc fc fc fc 03 fc fc fc fc fc fc fc
                                           ^
 ffff8801d1423580: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
 ffff8801d1423600: 00 fc fc fc fc fc fc fc fb fb fb fb fc fc fc fc
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