==================================================================
BUG: KASAN: use-after-free in leaf_paste_in_buffer+0x578/0x9f0
Read of size 48 at addr ffff0000e0ee8ff0 by task syz-executor.3/15911

CPU: 1 PID: 15911 Comm: syz-executor.3 Not tainted 5.15.118-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023
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
 memcpy+0x90/0xe8 mm/kasan/shadow.c:65
 leaf_paste_in_buffer+0x578/0x9f0
 leaf_copy_dir_entries+0x2b4/0xa04 fs/reiserfs/lbalance.c:108
 leaf_copy_boundary_item+0x8c4/0x1a34 fs/reiserfs/lbalance.c:168
 leaf_copy_items fs/reiserfs/lbalance.c:551 [inline]
 leaf_move_items+0xa0c/0x1f7c fs/reiserfs/lbalance.c:726
 leaf_shift_left+0xc8/0x39c fs/reiserfs/lbalance.c:750
 balance_leaf_insert_left fs/reiserfs/do_balan.c:339 [inline]
 balance_leaf_left fs/reiserfs/do_balan.c:611 [inline]
 balance_leaf+0x189c/0xe860 fs/reiserfs/do_balan.c:1409
 do_balance+0x27c/0x790 fs/reiserfs/do_balan.c:1888
 reiserfs_insert_item+0x940/0xa84 fs/reiserfs/stree.c:2261
 reiserfs_get_block+0x16ec/0x3fd0 fs/reiserfs/inode.c:876
 __block_write_begin_int+0x3ec/0x1608 fs/buffer.c:2012
 __block_write_begin+0x40/0x54 fs/buffer.c:2062
 reiserfs_write_begin+0x3c8/0x654 fs/reiserfs/inode.c:2790
 generic_perform_write+0x24c/0x520 mm/filemap.c:3776
 __generic_file_write_iter+0x230/0x454 mm/filemap.c:3903
 generic_file_write_iter+0xb4/0x1b8 mm/filemap.c:3935
 call_write_iter include/linux/fs.h:2103 [inline]
 new_sync_write fs/read_write.c:507 [inline]
 vfs_write+0x87c/0xb3c fs/read_write.c:594
 ksys_write+0x15c/0x26c fs/read_write.c:647
 __do_sys_write fs/read_write.c:659 [inline]
 __se_sys_write fs/read_write.c:656 [inline]
 __arm64_sys_write+0x7c/0x90 fs/read_write.c:656
 __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:00000000c54a4ec0 refcount:2 mapcount:0 mapping:00000000038d3082 index:0x214 pfn:0x120ee8
memcg:ffff0000d8898000
aops:def_blk_aops ino:700003
flags: 0x5ffc00000002032(referenced|lru|active|private|node=0|zone=2|lastcpupid=0x7ff)
raw: 05ffc00000002032 fffffc00040d57c8 fffffc000386ef08 ffff0000c058f288
raw: 0000000000000214 ffff0000cbfe6570 00000002ffffffff ffff0000d8898000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff0000e0ee8f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff0000e0ee8f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff0000e0ee9000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                   ^
 ffff0000e0ee9080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff0000e0ee9100: 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 1 0(1) DIR], item_len 35, item_location 3937, free_space(entry_count) 2
REISERFS error (device loop3): vs-5150 search_by_key: invalid format found in block 531. Fsck?
REISERFS (device loop3): Remounting filesystem read-only
REISERFS error (device loop3): vs-13050 reiserfs_update_sd_size: i/o failure occurred trying to update [2 3 0x0 SD] stat data
REISERFS warning: reiserfs-5093 is_leaf: item entry count seems wrong *3.5*[2 1 0(1) DIR], item_len 35, item_location 3937, free_space(entry_count) 2
REISERFS error (device loop3): vs-5150 search_by_key: invalid format found in block 531. Fsck?
REISERFS error (device loop3): vs-13050 reiserfs_update_sd_size: i/o failure occurred trying to update [2 3 0x0 SD] stat data