REISERFS (device loop5): journal params: device loop5, size 512, journal first block 18, max trans len 256, max batch 225, max commit age 30, max trans age 30
REISERFS (device loop5): checking transaction log (loop5)
REISERFS (device loop5): Using rupasov hash to sort names
REISERFS (device loop5): using 3.5.x disk format
==================================================================
BUG: KASAN: use-after-free in memmove include/linux/string.h:387 [inline]
BUG: KASAN: use-after-free in leaf_paste_entries+0x421/0x9b0 fs/reiserfs/lbalance.c:1369
Read of size 18446744073709486491 at addr ffff888049f7fe27 by task syz-executor.5/9975

CPU: 0 PID: 9975 Comm: syz-executor.5 Not tainted 4.14.212-syzkaller #0
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+0x1b2/0x283 lib/dump_stack.c:58
 print_address_description.cold+0x54/0x1d3 mm/kasan/report.c:252
 kasan_report_error.cold+0x8a/0x194 mm/kasan/report.c:351
 kasan_report+0x6f/0x7b mm/kasan/report.c:409
 memmove+0x20/0x50 mm/kasan/kasan.c:293
 memmove include/linux/string.h:387 [inline]
 leaf_paste_entries+0x421/0x9b0 fs/reiserfs/lbalance.c:1369
 balance_leaf_finish_node_paste_dirent fs/reiserfs/do_balan.c:1306 [inline]
 balance_leaf_finish_node_paste fs/reiserfs/do_balan.c:1332 [inline]
 balance_leaf_finish_node fs/reiserfs/do_balan.c:1375 [inline]
 balance_leaf+0x8298/0xbaa0 fs/reiserfs/do_balan.c:1463
 do_balance+0x27e/0x630 fs/reiserfs/do_balan.c:1899
 reiserfs_paste_into_item+0x569/0x6f0 fs/reiserfs/stree.c:2142
 reiserfs_add_entry+0x7d3/0xbc0 fs/reiserfs/namei.c:566
 reiserfs_mkdir+0x5ca/0x8b0 fs/reiserfs/namei.c:858
 create_privroot fs/reiserfs/xattr.c:880 [inline]
 reiserfs_xattr_init+0x393/0xa49 fs/reiserfs/xattr.c:1002
 reiserfs_fill_super+0x1b18/0x28be fs/reiserfs/super.c:2180
 mount_bdev+0x2b3/0x360 fs/super.c:1134
 mount_fs+0x92/0x2a0 fs/super.c:1237
 vfs_kern_mount.part.0+0x5b/0x470 fs/namespace.c:1046
 vfs_kern_mount fs/namespace.c:1036 [inline]
 do_new_mount fs/namespace.c:2549 [inline]
 do_mount+0xe53/0x2a00 fs/namespace.c:2879
 SYSC_mount fs/namespace.c:3095 [inline]
 SyS_mount+0xa8/0x120 fs/namespace.c:3072
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x460c7a
RSP: 002b:00007fd7e2b76a78 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fd7e2b76b10 RCX: 0000000000460c7a
RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007fd7e2b76ad0
RBP: 00007fd7e2b76ad0 R08: 00007fd7e2b76b10 R09: 0000000020000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000020000000
R13: 0000000020000100 R14: 0000000020000200 R15: 0000000020011400

The buggy address belongs to the page:
page:ffffea000127dfc0 count:0 mapcount:0 mapping:          (null) index:0x1
flags: 0xfff00000000000()
raw: 00fff00000000000 0000000000000000 0000000000000001 00000000ffffffff
raw: dead000000000100 dead000000000200 0000000000000000 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff888049f7fd00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888049f7fd80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff888049f7fe00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                               ^
 ffff888049f7fe80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888049f7ff00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================