==================================================================
BUG: KASAN: use-after-free in leaf_paste_in_buffer+0x578/0x9f0
Read of size 48 at addr ffff0000e7436ff0 by task syz.4.161/4897

CPU: 1 PID: 4897 Comm: syz.4.161 Not tainted 5.15.170-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
 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
 balance_leaf_when_delete_left fs/reiserfs/do_balan.c:167 [inline]
 balance_leaf_when_delete fs/reiserfs/do_balan.c:272 [inline]
 balance_leaf+0xa2a4/0xe860 fs/reiserfs/do_balan.c:1393
 do_balance+0x27c/0x790 fs/reiserfs/do_balan.c:1888
 reiserfs_cut_from_item+0x12b8/0x1c84 fs/reiserfs/stree.c:1838
 reiserfs_do_truncate+0x89c/0x11c8 fs/reiserfs/stree.c:1973
 reiserfs_truncate_file+0x3ac/0x6f0 fs/reiserfs/inode.c:2318
 reiserfs_setattr+0x8e8/0xd94 fs/reiserfs/inode.c:3409
 notify_change+0xa34/0xcf8 fs/attr.c:505
 do_truncate+0x1c0/0x28c fs/open.c:65
 do_sys_ftruncate+0x288/0x31c fs/open.c:193
 __do_sys_ftruncate fs/open.c:204 [inline]
 __se_sys_ftruncate fs/open.c:202 [inline]
 __arm64_sys_ftruncate+0x60/0x74 fs/open.c:202
 __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:0000000062e3840f refcount:2 mapcount:0 mapping:00000000b0b8ca5f index:0x21c pfn:0x127436
memcg:ffff0000d3db4000
aops:def_blk_aops ino:700004
flags: 0x5ffc00000002032(referenced|lru|active|private|node=0|zone=2|lastcpupid=0x7ff)
raw: 05ffc00000002032 fffffc00039d11c8 fffffc0003aa7e48 ffff0000c05488c8
raw: 000000000000021c ffff0000ddc31570 00000002ffffffff ffff0000d3db4000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff0000e7436f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff0000e7436f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff0000e7437000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                   ^
 ffff0000e7437080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff0000e7437100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================
REISERFS error (device loop4): vs-4010 is_reusable: block number is out of range 11822 (1024)
REISERFS (device loop4): Remounting filesystem read-only
REISERFS warning (device loop4): clm-6006 reiserfs_dirty_inode: writing inode 5 on readonly FS