UDF-fs: error (device loop6): udf_verify_fi: directory (ino 1376) has entry at pos 0 with incorrect tag 0
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BUG: KASAN: use-after-free in crc_itu_t+0x1f5/0x280 lib/crc-itu-t.c:60
Read of size 1 at addr ffff88802a5ed000 by task syz-executor/5415

CPU: 0 PID: 5415 Comm: syz-executor Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
 print_address_description+0x60/0x2d0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:434 [inline]
 kasan_report+0xdf/0x130 mm/kasan/report.c:451
 crc_itu_t+0x1f5/0x280 lib/crc-itu-t.c:60
 udf_finalize_lvid fs/udf/super.c:2057 [inline]
 udf_sync_fs+0x194/0x350 fs/udf/super.c:2413
 sync_filesystem+0xe6/0x220 fs/sync.c:56
 generic_shutdown_super+0x6b/0x300 fs/super.c:448
 kill_block_super+0x7c/0xe0 fs/super.c:1427
 deactivate_locked_super+0x93/0xf0 fs/super.c:335
 cleanup_mnt+0x418/0x4d0 fs/namespace.c:1139
 task_work_run+0x125/0x1a0 kernel/task_work.c:188
 exit_task_work include/linux/task_work.h:33 [inline]
 do_exit+0x61e/0x20a0 kernel/exit.c:883
 do_group_exit+0x12e/0x300 kernel/exit.c:997
 __do_sys_exit_group kernel/exit.c:1008 [inline]
 __se_sys_exit_group kernel/exit.c:1006 [inline]
 __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1006
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fea49079969
Code: Unable to access opcode bytes at RIP 0x7fea4907993f.
RSP: 002b:00007fff8cc5f898 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007fea490fb90f RCX: 00007fea49079969
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001
RBP: 0000000000000010 R08: 00007fff8cc5d636 R09: 00007fff8cc60b50
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fff8cc60b50
R13: 00007fea490fb89d R14: 00005555682ca4a8 R15: 00007fff8cc61c20
 </TASK>

The buggy address belongs to the page:
page:ffffea0000a97b40 refcount:0 mapcount:-128 mapping:0000000000000000 index:0x0 pfn:0x2a5ed
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 ffffea0001d63a88 ffffea00016fd6c8 0000000000000000
raw: 0000000000000000 0000000000000000 00000000ffffff7f 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as freed
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x100cc0(GFP_USER), pid 4876, ts 103285272615, free_ts 107185699726
 prep_new_page mm/page_alloc.c:2426 [inline]
 get_page_from_freelist+0x1b77/0x1c60 mm/page_alloc.c:4192
 __alloc_pages+0x1e1/0x470 mm/page_alloc.c:5487
 __get_free_pages+0x8/0x30 mm/page_alloc.c:5524
 kasan_populate_vmalloc_pte+0x21/0xc0 mm/kasan/shadow.c:266
 apply_to_pte_range mm/memory.c:2573 [inline]
 apply_to_pmd_range mm/memory.c:2617 [inline]
 apply_to_pud_range mm/memory.c:2653 [inline]
 apply_to_p4d_range mm/memory.c:2689 [inline]
 __apply_to_page_range+0x983/0xd10 mm/memory.c:2725
 alloc_vmap_area+0x19f7/0x1b20 mm/vmalloc.c:1572
 __get_vm_area_node+0x14f/0x2d0 mm/vmalloc.c:2430
 __vmalloc_node_range+0xef/0x8b0 mm/vmalloc.c:3027
 vmalloc_user+0x70/0x80 mm/vmalloc.c:3173
 kcov_mmap+0x27/0x120 kernel/kcov.c:474
 call_mmap include/linux/fs.h:2177 [inline]
 mmap_file+0x5d/0xb0 mm/util.c:1092
 __mmap_region mm/mmap.c:1796 [inline]
 mmap_region+0xf8f/0x1660 mm/mmap.c:2933
 do_mmap+0x81f/0xea0 mm/mmap.c:1586
 vm_mmap_pgoff+0x1b2/0x2b0 mm/util.c:551
 ksys_mmap_pgoff+0x542/0x780 mm/mmap.c:1635
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1340 [inline]
 free_pcp_prepare mm/page_alloc.c:1391 [inline]
 free_unref_page_prepare+0x637/0x6c0 mm/page_alloc.c:3317
 free_unref_page+0x94/0x280 mm/page_alloc.c:3396
 kasan_depopulate_vmalloc_pte+0x67/0x80 mm/kasan/shadow.c:375
 apply_to_pte_range mm/memory.c:2573 [inline]
 apply_to_pmd_range mm/memory.c:2617 [inline]
 apply_to_pud_range mm/memory.c:2653 [inline]
 apply_to_p4d_range mm/memory.c:2689 [inline]
 __apply_to_page_range+0x983/0xd10 mm/memory.c:2725
 kasan_release_vmalloc+0x93/0xb0 mm/kasan/shadow.c:485
 __purge_vmap_area_lazy+0xc6e/0x18f0 mm/vmalloc.c:1711
 _vm_unmap_aliases+0x410/0x4a0 mm/vmalloc.c:2114
 vm_remove_mappings mm/vmalloc.c:2591 [inline]
 __vunmap+0x70d/0xa40 mm/vmalloc.c:2618
 bpf_jit_binary_free kernel/bpf/core.c:918 [inline]
 bpf_jit_free+0x92/0x180 kernel/bpf/core.c:931
 process_one_work+0x863/0x1000 kernel/workqueue.c:2310
 worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287

Memory state around the buggy address:
 ffff88802a5ecf00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88802a5ecf80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88802a5ed000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                   ^
 ffff88802a5ed080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88802a5ed100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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