R13: 00000000004bddd0 R14: 00000000004d7140 R15: 0000000000000004
==================================================================
BUG: KASAN: slab-out-of-bounds in string+0x298/0x2d0 lib/vsprintf.c:604
Read of size 1 at addr ffff8801cdaa5e3a by task syz-executor4/8665

CPU: 0 PID: 8665 Comm: syz-executor4 Not tainted 4.19.0-rc6-next-20181003+ #86
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1d3/0x2c4 lib/dump_stack.c:113
 print_address_description.cold.8+0x9/0x1ff mm/kasan/report.c:256
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report.cold.9+0x242/0x309 mm/kasan/report.c:412
 __asan_report_load1_noabort+0x14/0x20 mm/kasan/report.c:430
 string+0x298/0x2d0 lib/vsprintf.c:604
 vsnprintf+0x48e/0x1b60 lib/vsprintf.c:2298
 vscnprintf+0x2d/0x80 lib/vsprintf.c:2401
 vprintk_store+0x43/0x510 kernel/printk/printk.c:1846
 vprintk_emit+0x1c1/0x930 kernel/printk/printk.c:1904
 vprintk_default+0x28/0x30 kernel/printk/printk.c:1962
 vprintk_func+0x7e/0x181 kernel/printk/printk_safe.c:398
 printk+0xa7/0xcf kernel/printk/printk.c:1995
 ovl_lookup_index.cold.14+0xe8/0x1f8 fs/overlayfs/namei.c:689
 ovl_lookup+0x9f2/0x29c0 fs/overlayfs/namei.c:1022
 __lookup_slow+0x2b5/0x540 fs/namei.c:1671
 lookup_slow+0x57/0x80 fs/namei.c:1688
 walk_component+0x92b/0x25b0 fs/namei.c:1810
 lookup_last fs/namei.c:2273 [inline]
 path_lookupat.isra.43+0x212/0xc00 fs/namei.c:2318
 filename_lookup+0x26a/0x520 fs/namei.c:2348
 user_path_at_empty+0x40/0x50 fs/namei.c:2608
 user_path_at include/linux/namei.h:57 [inline]
 path_setxattr+0xd6/0x230 fs/xattr.c:464
 __do_sys_setxattr fs/xattr.c:484 [inline]
 __se_sys_setxattr fs/xattr.c:480 [inline]
 __x64_sys_setxattr+0xc4/0x150 fs/xattr.c:480
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457579
Code: 1d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 eb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f6fa503bc78 EFLAGS: 00000246 ORIG_RAX: 00000000000000bc
RAX: ffffffffffffffda RBX: 00007f6fa503bc90 RCX: 0000000000457579
RDX: 00000000200006c0 RSI: 0000000020000680 RDI: 0000000020000640
RBP: 000000000072bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000014 R11: 0000000000000246 R12: 00007f6fa503c6d4
R13: 00000000004bddd0 R14: 00000000004d7140 R15: 0000000000000004

Allocated by task 8665:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 kasan_kmalloc+0xc7/0xe0 mm/kasan/kasan.c:553
 __do_kmalloc mm/slab.c:3718 [inline]
 __kmalloc+0x14e/0x760 mm/slab.c:3727
 kmalloc_array include/linux/slab.h:669 [inline]
 kcalloc include/linux/slab.h:680 [inline]
 ovl_get_index_name_fh+0x57/0x180 fs/overlayfs/namei.c:596
 ovl_get_index_name+0x5c/0x80 fs/overlayfs/namei.c:631
 ovl_lookup_index+0xe4/0x700 fs/overlayfs/namei.c:678
 ovl_lookup+0x9f2/0x29c0 fs/overlayfs/namei.c:1022
 __lookup_slow+0x2b5/0x540 fs/namei.c:1671
 lookup_slow+0x57/0x80 fs/namei.c:1688
 walk_component+0x92b/0x25b0 fs/namei.c:1810
 lookup_last fs/namei.c:2273 [inline]
 path_lookupat.isra.43+0x212/0xc00 fs/namei.c:2318
 filename_lookup+0x26a/0x520 fs/namei.c:2348
 user_path_at_empty+0x40/0x50 fs/namei.c:2608
 user_path_at include/linux/namei.h:57 [inline]
 path_setxattr+0xd6/0x230 fs/xattr.c:464
 __do_sys_setxattr fs/xattr.c:484 [inline]
 __se_sys_setxattr fs/xattr.c:480 [inline]
 __x64_sys_setxattr+0xc4/0x150 fs/xattr.c:480
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 6103:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 __kasan_slab_free+0x102/0x150 mm/kasan/kasan.c:521
 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528
 __cache_free mm/slab.c:3498 [inline]
 kfree+0xcf/0x230 mm/slab.c:3813
 __vunmap+0x335/0x460 mm/vmalloc.c:1532
 vfree+0x8b/0x140 mm/vmalloc.c:1597
 __do_replace+0x8c4/0xad0 net/ipv6/netfilter/ip6_tables.c:1113
 do_replace net/ipv6/netfilter/ip6_tables.c:1160 [inline]
 do_ip6t_set_ctl+0x49c/0x64b net/ipv6/netfilter/ip6_tables.c:1684
 nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
 nf_setsockopt+0x7d/0xd0 net/netfilter/nf_sockopt.c:115
 ipv6_setsockopt+0x105/0x170 net/ipv6/ipv6_sockglue.c:945
 tcp_setsockopt+0x93/0xe0 net/ipv4/tcp.c:3077
 sock_common_setsockopt+0x9a/0xe0 net/core/sock.c:3038
 __sys_setsockopt+0x1ba/0x3c0 net/socket.c:1903
 __do_sys_setsockopt net/socket.c:1914 [inline]
 __se_sys_setsockopt net/socket.c:1911 [inline]
 __x64_sys_setsockopt+0xbe/0x150 net/socket.c:1911
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff8801cdaa5e00
 which belongs to the cache kmalloc-64 of size 64
The buggy address is located 58 bytes inside of
 64-byte region [ffff8801cdaa5e00, ffff8801cdaa5e40)
The buggy address belongs to the page:
page:ffffea000736a940 count:1 mapcount:0 mapping:ffff8801da800340 index:0x0
flags: 0x2fffc0000000200(slab)
raw: 02fffc0000000200 ffffea0006eb5e88 ffffea0007369dc8 ffff8801da800340
raw: 0000000000000000 ffff8801cdaa5000 0000000100000020 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801cdaa5d00: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
 ffff8801cdaa5d80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
>ffff8801cdaa5e00: 00 00 00 00 00 00 00 02 fc fc fc fc fc fc fc fc
                                        ^
 ffff8801cdaa5e80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
 ffff8801cdaa5f00: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
==================================================================