REISERFS (device loop6): Created .reiserfs_priv - reserved for xattr storage.
==================================================================
BUG: KASAN: use-after-free in leaf_paste_entries+0x33c/0x924 fs/reiserfs/lbalance.c:1362
Read of size 2 at addr ffff0000f2c9000c by task syz.6.348/5886

CPU: 0 PID: 5886 Comm: syz.6.348 Not tainted 5.15.182-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
 __asan_report_load_n_noabort+0x40/0x4c mm/kasan/report_generic.c:319
 leaf_paste_entries+0x33c/0x924 fs/reiserfs/lbalance.c:1362
 leaf_copy_dir_entries+0x4dc/0x788 fs/reiserfs/lbalance.c:119
 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:00000000caeaaf7e refcount:0 mapcount:-128 mapping:0000000000000000 index:0x100 pfn:0x132c90
flags: 0x5ffc00000000000(node=0|zone=2|lastcpupid=0x7ff)
raw: 05ffc00000000000 fffffc0003cb3408 fffffc0003cb1408 0000000000000000
raw: 0000000000000100 0000000000000004 00000000ffffff7f 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff0000f2c8ff00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff0000f2c8ff80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff0000f2c90000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                      ^
 ffff0000f2c90080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff0000f2c90100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================
Unable to handle kernel write to read-only memory at virtual address ffff0000f1dd4ff0
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=0000000211394000
[ffff0000f1dd4ff0] pgd=180000023fff7003, p4d=180000023fff7003, pud=180000023f613003, pmd=180000023f484003, pte=0060000131dd4787
Internal error: Oops: 000000009600004f [#1] PREEMPT SMP
Modules linked in:
CPU: 1 PID: 5886 Comm: syz.6.348 Tainted: G    B             5.15.182-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025
pstate: a0400005 (NzCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : __memcpy+0x1d8/0x260 arch/arm64/lib/memcpy.S:220
lr : memmove+0xc8/0xe8 mm/kasan/shadow.c:58
sp : ffff800020086160
x29: ffff800020086160 x28: dfff800000000000 x27: 0000000000000000
x26: ffff0000f2c8e08b x25: 0000000000000020 x24: 00000000000ffff0
x23: ffff800016784000 x22: ffff800008c05e24 x21: ffff0000f2d8ef00
x20: ffff0000f2d8eee0 x19: fffffffffff00010 x18: 0000000000000002
x17: 0000000040000000 x16: ffff8000082d4b24 x15: 0000000000000002
x14: 0000000000000000 x13: d4202000d4202000 x12: d4202000d4202000
x11: d4202000d4202000 x10: d4202000d4202000 x9 : d4202000d4202000
x8 : d4202000d4202000 x7 : d4202000d4202000 x6 : d4202000d4202000
x5 : ffff0000f1dd5010 x4 : ffff0000f1dd4fb0 x3 : ffff800008c05e24
x2 : ffffffffff046090 x1 : ffff0000f2d8eee0 x0 : ffff0000f2d8ef00
Call trace:
 __memcpy+0x1d8/0x260 arch/arm64/lib/memcpy.S:219
 leaf_paste_entries+0x4d8/0x924 fs/reiserfs/lbalance.c:1377
 leaf_copy_dir_entries+0x4dc/0x788 fs/reiserfs/lbalance.c:119
 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
Code: f1020042 54000169 a93f1ca6 a97f1c86 (a93e24a8) 
---[ end trace 85322d30220bc933 ]---
----------------
Code disassembly (best guess):
   0:	f1020042 	subs	x2, x2, #0x80
   4:	54000169 	b.ls	0x30  // b.plast
   8:	a93f1ca6 	stp	x6, x7, [x5, #-16]
   c:	a97f1c86 	ldp	x6, x7, [x4, #-16]
* 10:	a93e24a8 	stp	x8, x9, [x5, #-32] <-- trapping instruction