REISERFS (device loop0): journal params: device loop0, size 512, journal first block 18, max trans len 256, max batch 225, max commit age 30, max trans age 30
REISERFS (device loop0): checking transaction log (loop0)
REISERFS (device loop0): Using r5 hash to sort names
==================================================================
BUG: KASAN: use-after-free in reiserfs_get_unused_objectid+0x1c4/0x3bc fs/reiserfs/objectid.c:87
Read of size 250888 at addr ffff0000e186d058 by task syz-executor.0/4537

CPU: 1 PID: 4537 Comm: syz-executor.0 Tainted: G        W          6.1.122-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call trace:
 dump_backtrace+0x1c8/0x1f4 arch/arm64/kernel/stacktrace.c:158
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x108/0x170 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:316 [inline]
 print_report+0x174/0x4c0 mm/kasan/report.c:427
 kasan_report+0xd4/0x130 mm/kasan/report.c:531
 kasan_check_range+0x264/0x2a4 mm/kasan/generic.c:189
 memmove+0x48/0x90 mm/kasan/shadow.c:54
 reiserfs_get_unused_objectid+0x1c4/0x3bc fs/reiserfs/objectid.c:87
 reiserfs_new_inode+0x238/0x1724 fs/reiserfs/inode.c:1944
 reiserfs_mkdir+0x4ac/0x77c fs/reiserfs/namei.c:845
 xattr_mkdir fs/reiserfs/xattr.c:76 [inline]
 create_privroot fs/reiserfs/xattr.c:882 [inline]
 reiserfs_xattr_init+0x2b0/0x6bc fs/reiserfs/xattr.c:1005
 reiserfs_fill_super+0x1bfc/0x2028 fs/reiserfs/super.c:2175
 mount_bdev+0x274/0x370 fs/super.c:1443
 get_super_block+0x44/0x58 fs/reiserfs/super.c:2601
 legacy_get_tree+0xd4/0x16c fs/fs_context.c:632
 vfs_get_tree+0x90/0x274 fs/super.c:1573
 do_new_mount+0x278/0x8fc fs/namespace.c:3056
 path_mount+0x590/0xe5c fs/namespace.c:3386
 do_mount fs/namespace.c:3399 [inline]
 __do_sys_mount fs/namespace.c:3607 [inline]
 __se_sys_mount fs/namespace.c:3584 [inline]
 __arm64_sys_mount+0x45c/0x594 fs/namespace.c:3584
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2bc arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140
 do_el0_svc+0x58/0x13c arch/arm64/kernel/syscall.c:204
 el0_svc+0x58/0x168 arch/arm64/kernel/entry-common.c:637
 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585

The buggy address belongs to the physical page:
page:00000000392fc4a4 refcount:3 mapcount:0 mapping:00000000cb9f506a index:0x10 pfn:0x12186d
memcg:ffff0000d439e000
aops:def_blk_aops ino:700000
flags: 0x5ffc20000002042(referenced|workingset|private|node=0|zone=2|lastcpupid=0x7ff)
raw: 05ffc20000002042 0000000000000000 dead000000000122 ffff0000c0499e10
raw: 0000000000000010 ffff0000dfc6f9f8 00000003ffffffff ffff0000d439e000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff0000e1872f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff0000e1872f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff0000e1873000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                   ^
 ffff0000e1873080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff0000e1873100: 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 3985, free_space(entry_count) 2
REISERFS error (device loop0): vs-5150 search_by_key: invalid format found in block 531. Fsck?
REISERFS (device loop0): Remounting filesystem read-only
REISERFS error (device loop0): vs-13050 reiserfs_update_sd_size: i/o failure occurred trying to update [2 1 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 3985, free_space(entry_count) 2
REISERFS error (device loop0): vs-5150 search_by_key: invalid format found in block 531. Fsck?
REISERFS error (device loop0): zam-7001 reiserfs_find_entry: io error
REISERFS warning: reiserfs-5093 is_leaf: item entry count seems wrong *3.5*[2 1 0(1) DIR], item_len 35, item_location 3985, free_space(entry_count) 2
REISERFS error (device loop0): vs-5150 search_by_key: invalid format found in block 531. Fsck?
REISERFS error (device loop0): vs-13050 reiserfs_update_sd_size: i/o failure occurred trying to update [2 1 0x0 SD] stat data
REISERFS warning (device loop0): jdm-20006 create_privroot: xattrs/ACLs enabled and couldn't find/create .reiserfs_priv. Failing mount.