==================================================================
BUG: KASAN: use-after-free in bin_search_in_dir_item fs/reiserfs/namei.c:40 [inline]
BUG: KASAN: use-after-free in search_by_entry_key+0x45c/0xe88 fs/reiserfs/namei.c:165
Read of size 4 at addr ffff000125c80004 by task syz-executor.5/28360

CPU: 0 PID: 28360 Comm: syz-executor.5 Not tainted 5.15.118-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
 __asan_report_load_n_noabort+0x40/0x4c mm/kasan/report_generic.c:319
 bin_search_in_dir_item fs/reiserfs/namei.c:40 [inline]
 search_by_entry_key+0x45c/0xe88 fs/reiserfs/namei.c:165
 reiserfs_find_entry+0x2a8/0x1624 fs/reiserfs/namei.c:322
 reiserfs_lookup+0x184/0x3c4 fs/reiserfs/namei.c:368
 __lookup_hash+0x108/0x230 fs/namei.c:1560
 filename_create+0x22c/0x464 fs/namei.c:3766
 do_mkdirat+0xac/0x610 fs/namei.c:4009
 __do_sys_mkdirat fs/namei.c:4034 [inline]
 __se_sys_mkdirat fs/namei.c:4032 [inline]
 __arm64_sys_mkdirat+0x90/0xa8 fs/namei.c:4032
 __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:00000000f169982b refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x165c80
flags: 0x5ffc00000000000(node=0|zone=2|lastcpupid=0x7ff)
raw: 05ffc00000000000 fffffc0004972048 fffffc0004bd03c8 0000000000000000
raw: 0000000000000001 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff000125c7ff00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff000125c7ff80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff000125c80000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                   ^
 ffff000125c80080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff000125c80100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================
REISERFS warning: reiserfs-5093 is_leaf: item entry count seems wrong *3.5*[2 3 0(1) DIR], item_len 35, item_location 4029, free_space(entry_count) 2
REISERFS error (device loop5): vs-5150 search_by_key: invalid format found in block 531. Fsck?
REISERFS (device loop5): Remounting filesystem read-only
REISERFS error (device loop5): vs-13050 reiserfs_update_sd_size: i/o failure occurred trying to update [2 3 0x0 SD] stat data