==================================================================
BUG: KASAN: out-of-bounds in leaf_paste_entries+0x504/0x944 fs/reiserfs/lbalance.c:1377
Read of size 18446744073709551600 at addr ffff000137e98f94 by task syz-executor.3/6845

CPU: 0 PID: 6845 Comm: syz-executor.3 Not tainted 5.15.117-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/25/2023
Call trace:
 dump_backtrace+0x0/0x530 arch/arm64/kernel/stacktrace.c:152
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:216
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x108/0x170 lib/dump_stack.c:106
 print_address_description+0x7c/0x3f0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:434 [inline]
 kasan_report+0x174/0x1e4 mm/kasan/report.c:451
 kasan_check_range+0x274/0x2b4 mm/kasan/generic.c:189
 memmove+0x90/0xe8 mm/kasan/shadow.c:54
 leaf_paste_entries+0x504/0x944 fs/reiserfs/lbalance.c:1377
 balance_leaf_finish_node_paste_dirent fs/reiserfs/do_balan.c:1295 [inline]
 balance_leaf_finish_node_paste fs/reiserfs/do_balan.c:1321 [inline]
 balance_leaf_finish_node fs/reiserfs/do_balan.c:1364 [inline]
 balance_leaf+0xa0d4/0xe860 fs/reiserfs/do_balan.c:1452
 do_balance+0x27c/0x790 fs/reiserfs/do_balan.c:1888
 reiserfs_paste_into_item+0x630/0x744 fs/reiserfs/stree.c:2159
 reiserfs_add_entry+0x8c0/0xc8c fs/reiserfs/namei.c:567
 reiserfs_mkdir+0x588/0x77c fs/reiserfs/namei.c:862
 xattr_mkdir fs/reiserfs/xattr.c:76 [inline]
 create_privroot fs/reiserfs/xattr.c:889 [inline]
 reiserfs_xattr_init+0x2b0/0x6dc fs/reiserfs/xattr.c:1012
 reiserfs_fill_super+0x1b28/0x1e8c fs/reiserfs/super.c:2179
 mount_bdev+0x274/0x370 fs/super.c:1378
 get_super_block+0x44/0x58 fs/reiserfs/super.c:2608
 legacy_get_tree+0xd4/0x16c fs/fs_context.c:610
 vfs_get_tree+0x90/0x274 fs/super.c:1508
 do_new_mount+0x25c/0x8c4 fs/namespace.c:2994
 path_mount+0x590/0x104c fs/namespace.c:3324
 do_mount fs/namespace.c:3337 [inline]
 __do_sys_mount fs/namespace.c:3545 [inline]
 __se_sys_mount fs/namespace.c:3522 [inline]
 __arm64_sys_mount+0x510/0x5e0 fs/namespace.c:3522
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
 el0_svc+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:596
 el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:614
 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584

The buggy address belongs to the page:
page:00000000e991bf8b refcount:3 mapcount:0 mapping:000000002b301250 index:0x213 pfn:0x177e98
memcg:ffff000125b90000
aops:def_blk_aops ino:700003
flags: 0x5ffc00000002022(referenced|active|private|node=0|zone=2|lastcpupid=0x7ff)
raw: 05ffc00000002022 0000000000000000 dead000000000122 ffff0000c058f288
raw: 0000000000000213 ffff00012dc62828 00000003ffffffff ffff000125b90000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff000137e98e80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff000137e98f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff000137e98f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
                         ^
 ffff000137e99000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff000137e99080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================
REISERFS (device loop3): Created .reiserfs_priv - reserved for xattr storage.