==================================================================
BUG: KASAN: use-after-free in udf_close_lvid+0x4d0/0x784 fs/udf/super.c:2105
Write of size 1 at addr ffff00012d381390 by task syz-executor/4321

CPU: 0 PID: 4321 Comm: syz-executor Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/26/2026
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_store1_noabort+0x2c/0x38 mm/kasan/report_generic.c:353
 udf_close_lvid+0x4d0/0x784 fs/udf/super.c:2105
 udf_put_super+0xb8/0x148 fs/udf/super.c:2392
 generic_shutdown_super+0x130/0x324 fs/super.c:501
 kill_block_super+0x70/0xdc fs/super.c:1470
 deactivate_locked_super+0xac/0x120 fs/super.c:332
 deactivate_super+0xe4/0x104 fs/super.c:363
 cleanup_mnt+0x390/0x418 fs/namespace.c:1191
 __cleanup_mnt+0x20/0x30 fs/namespace.c:1198
 task_work_run+0x1ec/0x278 kernel/task_work.c:203
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 do_notify_resume+0x1fa0/0x2aa4 arch/arm64/kernel/signal.c:1151
 prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:137 [inline]
 exit_to_user_mode arch/arm64/kernel/entry-common.c:142 [inline]
 el0_svc+0x98/0x128 arch/arm64/kernel/entry-common.c:638
 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:000000009a13100f refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x16d381
flags: 0x5ffc00000000000(node=0|zone=2|lastcpupid=0x7ff)
raw: 05ffc00000000000 fffffc0004b4e048 fffffc0004b4e048 0000000000000000
raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff00012d381280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff00012d381300: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff00012d381380: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                         ^
 ffff00012d381400: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff00012d381480: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================
EXT4-fs (loop0): unmounting filesystem.