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BUG: KASAN: slab-out-of-bounds in cap_inode_getsecurity+0x597/0x6e0 security/commoncap.c:408
Read of size 4 at addr ffff8801c3f983c0 by task syz-executor4/15057

CPU: 1 PID: 15057 Comm: syz-executor4 Not tainted 4.15.0-rc6-mm1+ #50
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+0x137/0x198 lib/dump_stack.c:53
 print_address_description+0x73/0x250 mm/kasan/report.c:256
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report+0x23b/0x360 mm/kasan/report.c:412
 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report.c:432
 cap_inode_getsecurity+0x597/0x6e0 security/commoncap.c:408
 security_inode_getsecurity+0xcd/0x110 security/security.c:809
 xattr_getsecurity+0x9c/0x130 fs/xattr.c:244
 vfs_getxattr+0xc8/0x110 fs/xattr.c:333
 getxattr+0x116/0x2a0 fs/xattr.c:540
 path_getxattr+0xcb/0x130 fs/xattr.c:568
 SYSC_getxattr fs/xattr.c:580 [inline]
 SyS_getxattr+0x33/0x40 fs/xattr.c:577
 entry_SYSCALL_64_fastpath+0x23/0x9a
RIP: 0033:0x452ac9
RSP: 002b:00007fd36acdcc58 EFLAGS: 00000212 ORIG_RAX: 00000000000000bf
RAX: ffffffffffffffda RBX: 00007fd36acdd700 RCX: 0000000000452ac9
RDX: 0000000020227f74 RSI: 0000000020b29f57 RDI: 0000000020fb6000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 000000000000038b R11: 0000000000000212 R12: 0000000000000000
R13: 0000000000a2f7ef R14: 00007fd36acdd9c0 R15: 0000000000000000

Allocated by task 15057:
 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:552
 __do_kmalloc mm/slab.c:3705 [inline]
 __kmalloc_track_caller+0x15e/0x760 mm/slab.c:3720
 __do_krealloc mm/slab_common.c:1449 [inline]
 krealloc+0x65/0xc0 mm/slab_common.c:1496
 vfs_getxattr_alloc+0x177/0x270 fs/xattr.c:290
 cap_inode_getsecurity+0xe1/0x6e0 security/commoncap.c:399
 security_inode_getsecurity+0xcd/0x110 security/security.c:809
 xattr_getsecurity+0x9c/0x130 fs/xattr.c:244
 vfs_getxattr+0xc8/0x110 fs/xattr.c:333
 getxattr+0x116/0x2a0 fs/xattr.c:540
 path_getxattr+0xcb/0x130 fs/xattr.c:568
 SYSC_getxattr fs/xattr.c:580 [inline]
 SyS_getxattr+0x33/0x40 fs/xattr.c:577
 entry_SYSCALL_64_fastpath+0x23/0x9a

Freed by task 12377:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 __kasan_slab_free+0x11a/0x170 mm/kasan/kasan.c:520
 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:527
 __cache_free mm/slab.c:3485 [inline]
 kfree+0xd9/0x260 mm/slab.c:3800
 dccp_feat_val_destructor+0xd2/0xf0 net/dccp/feat.c:388
 dccp_feat_entry_destructor net/dccp/feat.c:417 [inline]
 dccp_feat_list_purge+0xa9/0x170 net/dccp/feat.c:549
 dccp_destroy_sock+0x2f4/0x3f0 net/dccp/proto.c:236
 dccp_v6_destroy_sock+0x15/0x20 net/dccp/ipv6.c:1017
 inet_csk_destroy_sock+0x166/0x3f0 net/ipv4/inet_connection_sock.c:832
 dccp_close+0x853/0xc20 net/dccp/proto.c:1079
 inet_release+0xed/0x1c0 net/ipv4/af_inet.c:427
 inet6_release+0x50/0x70 net/ipv6/af_inet6.c:432
 sock_release+0x8d/0x1e0 net/socket.c:593
 SYSC_socketpair net/socket.c:1394 [inline]
 SyS_socketpair+0x438/0x520 net/socket.c:1338
 entry_SYSCALL_64_fastpath+0x23/0x9a

The buggy address belongs to the object at ffff8801c3f983c0
 which belongs to the cache kmalloc-32 of size 32
The buggy address is located 0 bytes inside of
 32-byte region [ffff8801c3f983c0, ffff8801c3f983e0)
The buggy address belongs to the page:
page:ffffea00070fe600 count:1 mapcount:0 mapping:ffff8801c3f98000 index:0xffff8801c3f98fc1
flags: 0x2fffc0000000100(slab)
raw: 02fffc0000000100 ffff8801c3f98000 ffff8801c3f98fc1 000000010000003c
raw: ffffea0007663be0 ffffea00075a89a0 ffff8801db0001c0 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801c3f98280: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
 ffff8801c3f98300: 00 fc fc fc fc fc fc fc fb fb fb fb fc fc fc fc
>ffff8801c3f98380: fb fb fb fb fc fc fc fc 01 fc fc fc fc fc fc fc
                                           ^
 ffff8801c3f98400: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
 ffff8801c3f98480: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
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