loop0: detected capacity change from 0 to 2048
UDF-fs: error (device loop0): udf_read_tagged: read failed, block=2362, location=2362
UDF-fs: error (device loop0): udf_read_tagged: tag checksum failed, block 99: 0x27 != 0x4d
UDF-fs: error (device loop0): udf_read_tagged: tag checksum failed, block 160: 0xd2 != 0xd4
UDF-fs: INFO Mounting volume 'LinuxUDF', timestamp 2022/11/22 14:59 (1000)

============================================
WARNING: possible recursive locking detected
syzkaller #0 Not tainted
--------------------------------------------
syz.0.0/5332 is trying to acquire lock:
ffff88801aff6120 (&sbi->s_alloc_mutex){+.+.}-{4:4}, at: udf_table_free_blocks fs/udf/balloc.c:376 [inline]
ffff88801aff6120 (&sbi->s_alloc_mutex){+.+.}-{4:4}, at: udf_free_blocks+0xa8c/0x1900 fs/udf/balloc.c:678

but task is already holding lock:
ffff88801aff6120 (&sbi->s_alloc_mutex){+.+.}-{4:4}, at: udf_table_new_block fs/udf/balloc.c:582 [inline]
ffff88801aff6120 (&sbi->s_alloc_mutex){+.+.}-{4:4}, at: udf_new_block+0xfb7/0x1c00 fs/udf/balloc.c:726

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(&sbi->s_alloc_mutex);
  lock(&sbi->s_alloc_mutex);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

4 locks held by syz.0.0/5332:
 #0: ffff88803299e450 (sb_writers#12){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:494
 #1: ffff88801f81c2f8 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1069 [inline]
 #1: ffff88801f81c2f8 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2918 [inline]
 #1: ffff88801f81c2f8 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2942 [inline]
 #1: ffff88801f81c2f8 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: filename_create+0x200/0x370 fs/namei.c:4955
 #2: ffff88801f81c0d8 (&ei->i_data_sem#3){++++}-{4:4}, at: udf_map_block+0x29c/0x4280 fs/udf/inode.c:445
 #3: ffff88801aff6120 (&sbi->s_alloc_mutex){+.+.}-{4:4}, at: udf_table_new_block fs/udf/balloc.c:582 [inline]
 #3: ffff88801aff6120 (&sbi->s_alloc_mutex){+.+.}-{4:4}, at: udf_new_block+0xfb7/0x1c00 fs/udf/balloc.c:726

stack backtrace:
CPU: 0 UID: 0 PID: 5332 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_deadlock_bug+0x279/0x290 kernel/locking/lockdep.c:3041
 check_deadlock kernel/locking/lockdep.c:3093 [inline]
 validate_chain kernel/locking/lockdep.c:3895 [inline]
 __lock_acquire+0x24df/0x2cf0 kernel/locking/lockdep.c:5237
 lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868
 __mutex_lock_common kernel/locking/mutex.c:646 [inline]
 __mutex_lock+0x19d/0x1550 kernel/locking/mutex.c:821
 udf_table_free_blocks fs/udf/balloc.c:376 [inline]
 udf_free_blocks+0xa8c/0x1900 fs/udf/balloc.c:678
 udf_delete_aext+0x4f5/0xc00 fs/udf/inode.c:2381
 udf_table_new_block fs/udf/balloc.c:646 [inline]
 udf_new_block+0x142f/0x1c00 fs/udf/balloc.c:726
 inode_getblk fs/udf/inode.c:900 [inline]
 udf_map_block+0x135a/0x4280 fs/udf/inode.c:453
 udf_bread+0x77/0x490 fs/udf/inode.c:1248
 udf_fiiter_append_blk+0x35e/0x870 fs/udf/directory.c:478
 udf_fiiter_add_entry+0x15cc/0x2000 fs/udf/namei.c:284
 udf_mkdir+0x25c/0x480 fs/udf/namei.c:455
 vfs_mkdir+0x406/0x620 fs/namei.c:5276
 filename_mkdirat+0x285/0x510 fs/namei.c:5309
 __do_sys_mkdirat fs/namei.c:5330 [inline]
 __se_sys_mkdirat+0x35/0x150 fs/namei.c:5327
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f549c59ccc7
Code: 00 66 90 48 89 f2 b9 00 01 00 00 48 89 fe bf 9c ff ff ff e9 db f7 ff ff 66 2e 0f 1f 84 00 00 00 00 00 90 b8 02 01 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f549d3aae18 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007f549d3aaea0 RCX: 00007f549c59ccc7
RDX: 00000000000001ff RSI: 0000200000000040 RDI: 00000000ffffff9c
RBP: 0000200000000000 R08: 00002000000000c0 R09: 0000000000000000
R10: 0000200000000000 R11: 0000000000000246 R12: 0000200000000040
R13: 00007f549d3aae60 R14: 0000000000000000 R15: 0000000000000000
 </TASK>