REISERFS (device loop0): Using r5 hash to sort names
REISERFS (device loop0): Created .reiserfs_priv - reserved for xattr storage.
==================================================================
BUG: KASAN: out-of-bounds in leaf_paste_in_buffer+0x1a8/0x9f0 fs/reiserfs/lbalance.c:1017
Read of size 18446744073709551365 at addr ffff0001890d7000 by task syz.0.16/5001

CPU: 1 PID: 5001 Comm: syz.0.16 Not tainted 5.15.179-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
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_in_buffer+0x1a8/0x9f0 fs/reiserfs/lbalance.c:1017
 balance_leaf_new_nodes_paste_whole fs/reiserfs/do_balan.c:1171 [inline]
 balance_leaf_new_nodes_paste fs/reiserfs/do_balan.c:1215 [inline]
 balance_leaf_new_nodes fs/reiserfs/do_balan.c:1246 [inline]
 balance_leaf+0x5eec/0xe860 fs/reiserfs/do_balan.c:1450
 do_balance+0x27c/0x790 fs/reiserfs/do_balan.c:1888
 reiserfs_paste_into_item+0x630/0x744 fs/reiserfs/stree.c:2159
 reiserfs_get_block+0x1820/0x3fd0 fs/reiserfs/inode.c:1077
 __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:3785
 __generic_file_write_iter+0x230/0x454 mm/filemap.c:3912
 generic_file_write_iter+0xb4/0x1b8 mm/filemap.c:3944
 call_write_iter include/linux/fs.h:2172 [inline]
 new_sync_write fs/read_write.c:507 [inline]
 vfs_write+0x884/0xb44 fs/read_write.c:594
 ksys_pwrite64 fs/read_write.c:701 [inline]
 __do_sys_pwrite64 fs/read_write.c:711 [inline]
 __se_sys_pwrite64 fs/read_write.c:708 [inline]
 __arm64_sys_pwrite64+0x188/0x220 fs/read_write.c:708
 __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:000000003ab857a1 refcount:6 mapcount:4 mapping:00000000032eea3f index:0x1f5 pfn:0x1c90d7
memcg:ffff0000c08a4000
aops:ext4_da_aops ino:6c7 dentry name:"syz-executor"
flags: 0x5ffc0000000283c(uptodate|dirty|lru|active|arch_1|private|node=0|zone=2|lastcpupid=0x7ff)
raw: 05ffc0000000283c fffffc0005863ac8 fffffc0003773708 ffff0000dc2d7270
raw: 00000000000001f5 ffff0000d428ae80 0000000600000003 ffff0000c08a4000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff0001890d6f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff0001890d6f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff0001890d7000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
                   ^
 ffff0001890d7080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff0001890d7100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================
REISERFS warning: reiserfs-5090 is_tree_node: node level 0 does not match to the expected one 1
REISERFS error (device loop0): vs-5150 search_by_key: invalid format found in block 531. Fsck?
REISERFS (device loop0): Remounting filesystem read-only