REISERFS (device loop7): Created .reiserfs_priv - reserved for xattr storage.
==================================================================
BUG: KASAN: use-after-free in leaf_paste_entries+0x99c/0xae4 fs/reiserfs/lbalance.c:1351
Read of size 2 at addr ffff0000fcd52edc by task syz.7.745/7786

CPU: 0 PID: 7786 Comm: syz.7.745 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/03/2025
Call trace:
 dump_backtrace+0x1c0/0x1ec arch/arm64/kernel/stacktrace.c:158
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165
 __dump_stack+0x30/0x40 lib/dump_stack.c:88
 dump_stack_lvl+0xf4/0x15c lib/dump_stack.c:106
 print_address_description+0x88/0x218 mm/kasan/report.c:316
 print_report+0x50/0x68 mm/kasan/report.c:420
 kasan_report+0xa8/0xfc mm/kasan/report.c:524
 __asan_report_load_n_noabort+0x28/0x34 mm/kasan/report_generic.c:361
 leaf_paste_entries+0x99c/0xae4 fs/reiserfs/lbalance.c:1351
 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+0x6a0/0xbb0 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+0x27b0/0xd92c fs/reiserfs/do_balan.c:1393
 do_balance+0x270/0x790 fs/reiserfs/do_balan.c:1888
 reiserfs_cut_from_item+0x114c/0x1a14 fs/reiserfs/stree.c:1838
 reiserfs_do_truncate+0x738/0x1058 fs/reiserfs/stree.c:1973
 reiserfs_truncate_file+0x5d0/0xb00 fs/reiserfs/inode.c:2310
 reiserfs_setattr+0xab4/0xfec fs/reiserfs/inode.c:3395
 notify_change+0xb0c/0xdcc fs/attr.c:499
 do_truncate+0x188/0x20c fs/open.c:65
 handle_truncate fs/namei.c:3293 [inline]
 do_open fs/namei.c:3638 [inline]
 path_openat+0x2110/0x26bc fs/namei.c:3791
 do_filp_open+0x194/0x384 fs/namei.c:3818
 do_sys_openat2+0x134/0x3f4 fs/open.c:1320
 do_sys_open fs/open.c:1336 [inline]
 __do_sys_openat fs/open.c:1352 [inline]
 __se_sys_openat fs/open.c:1347 [inline]
 __arm64_sys_openat+0x118/0x14c fs/open.c:1347
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2b4 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140
 do_el0_svc+0x58/0x130 arch/arm64/kernel/syscall.c:204
 el0_svc+0x58/0x128 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:00000000e318e9cc refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x13cd52
flags: 0x5ffc00000000000(node=0|zone=2|lastcpupid=0x7ff)
raw: 05ffc00000000000 dead000000000100 dead000000000122 0000000000000000
raw: 0000000000000001 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff0000fcd52d80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff0000fcd52e00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff0000fcd52e80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                                    ^
 ffff0000fcd52f00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff0000fcd52f80: 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 ffff0000fbee1ff0
KASAN: maybe wild-memory-access in range [0xfffc0007df70ff80-0xfffc0007df70ff87]
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=000000020dfb9000
[ffff0000fbee1ff0] pgd=180000023fff8003, p4d=180000023fff8003, pud=180000023f414003, pmd=180000023f234003, pte=006000013bee1787
Internal error: Oops: 000000009600004f [#1] PREEMPT SMP
Modules linked in:
CPU: 0 PID: 7786 Comm: syz.7.745 Tainted: G    B              syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/03/2025
pstate: a2400005 (NzCv daif +PAN -UAO +TCO -DIT -SSBS BTYPE=--)
pc : __memcpy+0x1d8/0x260 arch/arm64/lib/memcpy.S:217
lr : memmove+0x74/0x90 mm/kasan/shadow.c:58
sp : ffff800021406140
x29: ffff800021406140 x28: dfff800000000000 x27: ffff0000e4e5ffd0
x26: ffff0000fcc5208b x25: ffff0000fcc5208a x24: 00000000000ffff0
x23: 0000000000000020 x22: ffff800008cc43d8 x21: ffff0000fcd52f00
x20: ffff0000fcd52ee0 x19: fffffffffff00010 x18: ffff800011b8bf60
x17: 0000000000000000 x16: ffff80000804309c x15: 0000000000000000
x14: 0000000000000000 x13: d4202000d4202000 x12: d4202000d4202000
x11: d4202000d4202000 x10: d4202000d4202000 x9 : d4202000d4202000
x8 : d4202000d4202000 x7 : d4202000d4202000 x6 : d4202000d4202000
x5 : ffff0000fbee2010 x4 : ffff0000fbee1fb0 x3 : ffff800008cc43d8
x2 : ffffffffff18f090 x1 : ffff0000fcd52ee0 x0 : ffff0000fcd52f00
Call trace:
 __memcpy+0x1d8/0x260 arch/arm64/lib/memcpy.S:216
 leaf_paste_entries+0x69c/0xae4 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+0x6a0/0xbb0 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+0x27b0/0xd92c fs/reiserfs/do_balan.c:1393
 do_balance+0x270/0x790 fs/reiserfs/do_balan.c:1888
 reiserfs_cut_from_item+0x114c/0x1a14 fs/reiserfs/stree.c:1838
 reiserfs_do_truncate+0x738/0x1058 fs/reiserfs/stree.c:1973
 reiserfs_truncate_file+0x5d0/0xb00 fs/reiserfs/inode.c:2310
 reiserfs_setattr+0xab4/0xfec fs/reiserfs/inode.c:3395
 notify_change+0xb0c/0xdcc fs/attr.c:499
 do_truncate+0x188/0x20c fs/open.c:65
 handle_truncate fs/namei.c:3293 [inline]
 do_open fs/namei.c:3638 [inline]
 path_openat+0x2110/0x26bc fs/namei.c:3791
 do_filp_open+0x194/0x384 fs/namei.c:3818
 do_sys_openat2+0x134/0x3f4 fs/open.c:1320
 do_sys_open fs/open.c:1336 [inline]
 __do_sys_openat fs/open.c:1352 [inline]
 __se_sys_openat fs/open.c:1347 [inline]
 __arm64_sys_openat+0x118/0x14c fs/open.c:1347
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2b4 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140
 do_el0_svc+0x58/0x130 arch/arm64/kernel/syscall.c:204
 el0_svc+0x58/0x128 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
Code: f1020042 54000169 a93f1ca6 a97f1c86 (a93e24a8) 
---[ end trace 0000000000000000 ]---
----------------
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