REISERFS (device loop3): Using tea hash to sort names
REISERFS (device loop3): Created .reiserfs_priv - reserved for xattr storage.
==================================================================
BUG: KASAN: use-after-free in leaf_paste_in_buffer+0x650/0xa0c fs/reiserfs/lbalance.c:-1
Read of size 48 at addr ffff0000f3abcff0 by task syz.3.489/6769

CPU: 0 PID: 6769 Comm: syz.3.489 Not tainted 5.15.181-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025
Call trace:
 dump_backtrace+0x0/0x43c arch/arm64/kernel/stacktrace.c:152
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:216
 __dump_stack+0x30/0x40 lib/dump_stack.c:88
 dump_stack_lvl+0xf8/0x160 lib/dump_stack.c:106
 print_address_description+0x78/0x30c mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:434 [inline]
 kasan_report+0xec/0x15c mm/kasan/report.c:451
 check_region_inline mm/kasan/generic.c:-1 [inline]
 kasan_check_range+0x270/0x2b0 mm/kasan/generic.c:189
 memcpy+0x90/0xe8 mm/kasan/shadow.c:65
 leaf_paste_in_buffer+0x650/0xa0c fs/reiserfs/lbalance.c:-1
 leaf_copy_dir_entries+0x45c/0x788 fs/reiserfs/lbalance.c:108
 leaf_copy_boundary_item+0x888/0x19dc fs/reiserfs/lbalance.c:-1
 leaf_copy_items fs/reiserfs/lbalance.c:551 [inline]
 leaf_move_items+0x694/0xb9c fs/reiserfs/lbalance.c:726
 leaf_shift_left+0xc8/0x3ac fs/reiserfs/lbalance.c:750
 balance_leaf_when_delete_left fs/reiserfs/do_balan.c:194 [inline]
 balance_leaf_when_delete fs/reiserfs/do_balan.c:272 [inline]
 balance_leaf+0x182c/0xd2f4 fs/reiserfs/do_balan.c:1393
 do_balance+0x260/0x778 fs/reiserfs/do_balan.c:1888
 reiserfs_cut_from_item+0x1184/0x1a44 fs/reiserfs/stree.c:1838
 reiserfs_do_truncate+0x738/0x1020 fs/reiserfs/stree.c:1973
 reiserfs_truncate_file+0x328/0x6e4 fs/reiserfs/inode.c:2318
 reiserfs_setattr+0x8c8/0xd70 fs/reiserfs/inode.c:3409
 notify_change+0xa08/0xcd8 fs/attr.c:505
 do_truncate+0x178/0x1f0 fs/open.c:65
 handle_truncate fs/namei.c:3265 [inline]
 do_open fs/namei.c:3612 [inline]
 path_openat+0x211c/0x26e4 fs/namei.c:3742
 do_filp_open+0x164/0x330 fs/namei.c:3769
 do_sys_openat2+0x128/0x3d8 fs/open.c:1253
 do_sys_open fs/open.c:1269 [inline]
 __do_sys_openat fs/open.c:1285 [inline]
 __se_sys_openat fs/open.c:1280 [inline]
 __arm64_sys_openat+0x120/0x154 fs/open.c:1280
 __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+0x78/0x1e0 arch/arm64/kernel/entry-common.c:608
 el0t_64_sync_handler+0xcc/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:000000008d62bd9a refcount:2 mapcount:0 mapping:000000004464d929 index:0x214 pfn:0x133abc
memcg:ffff0000d92e0000
aops:def_blk_aops ino:700003
flags: 0x5ffc00000002032(referenced|lru|active|private|node=0|zone=2|lastcpupid=0x7ff)
raw: 05ffc00000002032 fffffc0003cea008 ffff0000d8ef7030 ffff0000c04a08c8
raw: 0000000000000214 ffff0000de374cb0 00000002ffffffff ffff0000d92e0000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff0000f3abcf00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff0000f3abcf80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff0000f3abd000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
                   ^
 ffff0000f3abd080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff0000f3abd100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================
Unable to handle kernel write to read-only memory at virtual address ffff0000f4f2dff0
Mem abort info:
  ESR = 0x000000009600004f
  EC = 0x25: DABT (current EL), IL = 32 bits
  SET = 0, FnV = 0
  EA = 0, S1PTW = 0
  FSC = 0x0f: level 3 permission fault
Data abort info:
  ISV = 0, ISS = 0x0000004f
  CM = 0, WnR = 1
swapper pgtable: 4k pages, 48-bit VAs, pgdp=00000001af594000
[ffff0000f4f2dff0] pgd=180000023fff7003
, p4d=180000023fff7003
, pud=180000023f613003
, pmd=180000023f46b003
, pte=0060000134f2d787