==================================================================
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 ffff0000e9bd0f3c by task syz.7.293/6062

CPU: 1 PID: 6062 Comm: syz.7.293 Not tainted 5.15.171-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
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+0xdbc/0x1624 fs/reiserfs/namei.c:322
 reiserfs_lookup+0x184/0x3c4 fs/reiserfs/namei.c:368
 lookup_one_qstr_excl+0x108/0x230 fs/namei.c:1563
 filename_create+0x230/0x468 fs/namei.c:3836
 do_mkdirat+0xac/0x610 fs/namei.c:4080
 __do_sys_mkdirat fs/namei.c:4105 [inline]
 __se_sys_mkdirat fs/namei.c:4103 [inline]
 __arm64_sys_mkdirat+0x90/0xa8 fs/namei.c:4103
 __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:608
 el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626
 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584

The buggy address belongs to the page:
page:0000000041d704f4 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x129bd0
flags: 0x5ffc00000000000(node=0|zone=2|lastcpupid=0x7ff)
raw: 05ffc00000000000 fffffc0003a6f448 fffffc00039e5448 0000000000000000
raw: 0000000000000001 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff0000e9bd0e00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff0000e9bd0e80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff0000e9bd0f00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                        ^
 ffff0000e9bd0f80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff0000e9bd1000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================
REISERFS warning (device loop7): vs-13060 reiserfs_update_sd_size: stat data of object [2 5 0x0 SD] (nlink == 3) not found (pos 4)