============================================
WARNING: possible recursive locking detected
syzkaller #0 Not tainted
--------------------------------------------
syz.4.18/4484 is trying to acquire lock:
ffff888054c01928 (&sbi->s_alloc_mutex){+.+.}-{3:3}, at: udf_table_free_blocks fs/udf/balloc.c:396 [inline]
ffff888054c01928 (&sbi->s_alloc_mutex){+.+.}-{3:3}, at: udf_free_blocks+0x9a0/0x17f0 fs/udf/balloc.c:687

but task is already holding lock:
ffff888054c01928 (&sbi->s_alloc_mutex){+.+.}-{3:3}, at: udf_table_new_block fs/udf/balloc.c:595 [inline]
ffff888054c01928 (&sbi->s_alloc_mutex){+.+.}-{3:3}, at: udf_new_block+0xe15/0x1990 fs/udf/balloc.c:735

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

2 locks held by syz.4.18/4484:
 #0: ffff88802c538460 (sb_writers#18){.+.+}-{0:0}, at: mnt_want_write+0x3d/0x90 fs/namespace.c:402
 #1: ffff888054c01928 (&sbi->s_alloc_mutex){+.+.}-{3:3}, at: udf_table_new_block fs/udf/balloc.c:595 [inline]
 #1: ffff888054c01928 (&sbi->s_alloc_mutex){+.+.}-{3:3}, at: udf_new_block+0xe15/0x1990 fs/udf/balloc.c:735

stack backtrace:
CPU: 0 PID: 4484 Comm: syz.4.18 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106
 __lock_acquire+0x12c8/0x7c40 kernel/locking/lockdep.c:-1
 lock_acquire+0x1bb/0x4a0 kernel/locking/lockdep.c:5676
 __mutex_lock_common kernel/locking/mutex.c:603 [inline]
 __mutex_lock+0x12d/0xae0 kernel/locking/mutex.c:747
 udf_table_free_blocks fs/udf/balloc.c:396 [inline]
 udf_free_blocks+0x9a0/0x17f0 fs/udf/balloc.c:687
 udf_delete_aext+0x4c4/0xba0 fs/udf/inode.c:2210
 udf_table_new_block fs/udf/balloc.c:655 [inline]
 udf_new_block+0x122f/0x1990 fs/udf/balloc.c:735
 udf_new_inode+0x358/0xe60 fs/udf/ialloc.c:86
 udf_tmpfile+0x21/0x170 fs/udf/namei.c:387
 vfs_tmpfile+0x307/0x470 fs/namei.c:3685
 do_tmpfile+0xd4/0x240 fs/namei.c:3748
 path_openat+0x290c/0x2f10 fs/namei.c:3782
 do_filp_open+0x1ee/0x420 fs/namei.c:3818
 do_sys_openat2+0x14b/0x4f0 fs/open.c:1320
 do_sys_open fs/open.c:1336 [inline]
 __do_sys_open fs/open.c:1344 [inline]
 __se_sys_open fs/open.c:1340 [inline]
 __x64_sys_open+0x11b/0x140 fs/open.c:1340
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f497cb9de99
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f497add5028 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 00007f497ce26090 RCX: 00007f497cb9de99
RDX: 0000000000000000 RSI: 0000000000511082 RDI: 0000200000000040
RBP: 00007f497cc33eaf R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f497ce26128 R14: 00007f497ce26090 R15: 00007ffcdaa172f8
 </TASK>