============================================
WARNING: possible recursive locking detected
6.16.0-rc2-syzkaller-00082-gfb4d33ab452e #0 Not tainted
--------------------------------------------
syz.0.0/5330 is trying to acquire lock:
ffff888035994928 (&sbi->s_alloc_mutex){+.+.}-{4:4}, at: udf_table_free_blocks fs/udf/balloc.c:375 [inline]
ffff888035994928 (&sbi->s_alloc_mutex){+.+.}-{4:4}, at: udf_free_blocks+0x9e2/0x17f0 fs/udf/balloc.c:677

but task is already holding lock:
ffff888035994928 (&sbi->s_alloc_mutex){+.+.}-{4:4}, at: udf_table_new_block fs/udf/balloc.c:581 [inline]
ffff888035994928 (&sbi->s_alloc_mutex){+.+.}-{4:4}, at: udf_new_block+0xfab/0x1ba0 fs/udf/balloc.c:725

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

3 locks held by syz.0.0/5330:
 #0: ffff888036404428 (sb_writers#12){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:557
 #1: ffff888052830900 (&type->i_mutex_dir_key#8){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:869 [inline]
 #1: ffff888052830900 (&type->i_mutex_dir_key#8){+.+.}-{4:4}, at: open_last_lookups fs/namei.c:3813 [inline]
 #1: ffff888052830900 (&type->i_mutex_dir_key#8){+.+.}-{4:4}, at: path_openat+0x8da/0x3830 fs/namei.c:4052
 #2: ffff888035994928 (&sbi->s_alloc_mutex){+.+.}-{4:4}, at: udf_table_new_block fs/udf/balloc.c:581 [inline]
 #2: ffff888035994928 (&sbi->s_alloc_mutex){+.+.}-{4:4}, at: udf_new_block+0xfab/0x1ba0 fs/udf/balloc.c:725

stack backtrace:
CPU: 0 UID: 0 PID: 5330 Comm: syz.0.0 Not tainted 6.16.0-rc2-syzkaller-00082-gfb4d33ab452e #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 print_deadlock_bug+0x28b/0x2a0 kernel/locking/lockdep.c:3044
 check_deadlock kernel/locking/lockdep.c:3096 [inline]
 validate_chain+0x1a3f/0x2140 kernel/locking/lockdep.c:3898
 __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5240
 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871
 __mutex_lock_common kernel/locking/mutex.c:602 [inline]
 __mutex_lock+0x182/0xe80 kernel/locking/mutex.c:747
 udf_table_free_blocks fs/udf/balloc.c:375 [inline]
 udf_free_blocks+0x9e2/0x17f0 fs/udf/balloc.c:677
 udf_delete_aext+0x4df/0xbc0 fs/udf/inode.c:2373
 udf_table_new_block fs/udf/balloc.c:645 [inline]
 udf_new_block+0x1404/0x1ba0 fs/udf/balloc.c:725
 udf_new_inode+0x399/0xd50 fs/udf/ialloc.c:67
 udf_create+0x23/0xf0 fs/udf/namei.c:376
 lookup_open fs/namei.c:3717 [inline]
 open_last_lookups fs/namei.c:3816 [inline]
 path_openat+0x14f4/0x3830 fs/namei.c:4052
 do_filp_open+0x1fa/0x410 fs/namei.c:4082
 do_sys_openat2+0x121/0x1c0 fs/open.c:1437
 do_sys_open fs/open.c:1452 [inline]
 __do_sys_openat fs/open.c:1468 [inline]
 __se_sys_openat fs/open.c:1463 [inline]
 __x64_sys_openat+0x138/0x170 fs/open.c:1463
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fef8938e929
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fef8a12f038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fef895b6240 RCX: 00007fef8938e929
RDX: 000000000000275a RSI: 0000200000000040 RDI: ffffffffffffff9c
RBP: 00007fef89410b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000001 R14: 00007fef895b6240 R15: 00007ffc34dba2b8
 </TASK>