audit: type=1400 audit(1514539432.837:7): avc:  denied  { map } for  pid=3159 comm="syzkaller841149" path="/root/syzkaller841149303" dev="sda1" ino=16481 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1
==================================================================
BUG: KASAN: slab-out-of-bounds in cap_convert_nscap+0x501/0x610 security/commoncap.c:498
Read of size 4 at addr ffff8801c8d031c0 by task syzkaller841149/3159

CPU: 1 PID: 3159 Comm: syzkaller841149 Not tainted 4.15.0-rc5+ #150
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
 do_syscall_32_irqs_on arch/x86/entry/common.c:327 [inline]
 do_fast_syscall_32+0x3ee/0xf9d arch/x86/entry/common.c:389
 entry_SYSENTER_compat+0x54/0x63 arch/x86/entry/entry_64_compat.S:125
RIP: 0023:0xf7fa7c79
RSP: 002b:00000000ffd39c6c EFLAGS: 00000282 ORIG_RAX: 00000000000000e4
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000020d4bfe8
RDX: 00000000209b8000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000

Allocated by task 3159:
 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
 do_syscall_32_irqs_on arch/x86/entry/common.c:327 [inline]
 do_fast_syscall_32+0x3ee/0xf9d arch/x86/entry/common.c:389
 entry_SYSENTER_compat+0x54/0x63 arch/x86/entry/entry_64_compat.S:125

Freed by task 1644:
 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
 security_inode_init_security+0x1c3/0x390 security/security.c:494
 shmem_mknod+0x9b/0x1b0 mm/shmem.c:2995
 shmem_create+0x2b/0x40 mm/shmem.c:3050
 lookup_open+0x1217/0x1970 fs/namei.c:3200
 do_last fs/namei.c:3291 [inline]
 path_openat+0xd76/0x3530 fs/namei.c:3519
 do_filp_open+0x25b/0x3b0 fs/namei.c:3554
 do_sys_open+0x502/0x6d0 fs/open.c:1059
 SYSC_open fs/open.c:1077 [inline]
 SyS_open+0x2d/0x40 fs/open.c:1072
 entry_SYSCALL_64_fastpath+0x1f/0x96

The buggy address belongs to the object at ffff8801c8d031c0
 which belongs to the cache kmalloc-32 of size 32
The buggy address is located 0 bytes inside of
 32-byte region [ffff8801c8d031c0, ffff8801c8d031e0)
The buggy address belongs to the page:
page:00000000bd743ed1 count:1 mapcount:0 mapping:00000000690d0687 index:0xffff8801c8d03fc1
flags: 0x2fffc0000000100(slab)
raw: 02fffc0000000100 ffff8801c8d03000 ffff8801c8d03fc1 000000010000003f
raw: ffffea000723dc20 ffffea000721b820 ffff8801db0001c0 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801c8d03080: fb fb fb fb fc fc fc fc 00 04 fc fc fc fc fc fc
 ffff8801c8d03100: 00 00 01 fc fc fc fc fc 00 00 00 fc fc fc fc fc
>ffff8801c8d03180: fb fb fb fb fc fc fc fc 01 fc fc fc fc fc fc fc
                                           ^
 ffff8801c8d03200: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
 ffff8801c8d03280: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
==================================================================