============================================
WARNING: possible recursive locking detected
6.13.0-rc1-syzkaller-00025-gfeffde684ac2 #0 Not tainted
--------------------------------------------
syz.0.26/6664 is trying to acquire lock:
ffff888028c98128 (&sbi->s_alloc_mutex){+.+.}-{4:4}, at: udf_table_free_blocks fs/udf/balloc.c:375 [inline]
ffff888028c98128 (&sbi->s_alloc_mutex){+.+.}-{4:4}, at: udf_free_blocks+0x9f1/0x2260 fs/udf/balloc.c:677

but task is already holding lock:
ffff888028c98128 (&sbi->s_alloc_mutex){+.+.}-{4:4}, at: udf_table_new_block fs/udf/balloc.c:581 [inline]
ffff888028c98128 (&sbi->s_alloc_mutex){+.+.}-{4:4}, at: udf_new_block+0xf79/0x21c0 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

4 locks held by syz.0.26/6664:
 #0: ffff888063136420 (sb_writers#13){.+.+}-{0:0}, at: direct_splice_actor+0x45/0x210 fs/splice.c:1163
 #1: ffff888061d2f560 (&sb->s_type->i_mutex_key#21){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:818 [inline]
 #1: ffff888061d2f560 (&sb->s_type->i_mutex_key#21){+.+.}-{4:4}, at: udf_file_write_iter+0x6b/0x660 fs/udf/file.c:95
 #2: ffff888061d2f390 (&ei->i_data_sem#2){++++}-{4:4}, at: udf_map_block+0x3b3/0x5330 fs/udf/inode.c:439
 #3: ffff888028c98128 (&sbi->s_alloc_mutex){+.+.}-{4:4}, at: udf_table_new_block fs/udf/balloc.c:581 [inline]
 #3: ffff888028c98128 (&sbi->s_alloc_mutex){+.+.}-{4:4}, at: udf_new_block+0xf79/0x21c0 fs/udf/balloc.c:725

stack backtrace:
CPU: 0 UID: 0 PID: 6664 Comm: syz.0.26 Not tainted 6.13.0-rc1-syzkaller-00025-gfeffde684ac2 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x23d/0x360 lib/dump_stack.c:120
 print_deadlock_bug+0x476/0x620 kernel/locking/lockdep.c:3037
 check_deadlock kernel/locking/lockdep.c:3089 [inline]
 validate_chain kernel/locking/lockdep.c:3891 [inline]
 __lock_acquire+0x60d7/0x81c0 kernel/locking/lockdep.c:5226
 lock_acquire+0x1e9/0x540 kernel/locking/lockdep.c:5849
 __mutex_lock_common kernel/locking/mutex.c:585 [inline]
 __mutex_lock+0x1a8/0xed0 kernel/locking/mutex.c:735
 udf_table_free_blocks fs/udf/balloc.c:375 [inline]
 udf_free_blocks+0x9f1/0x2260 fs/udf/balloc.c:677
 udf_delete_aext+0x706/0xed0 fs/udf/inode.c:2372
 udf_table_new_block fs/udf/balloc.c:645 [inline]
 udf_new_block+0x18b2/0x21c0 fs/udf/balloc.c:725
 inode_getblk fs/udf/inode.c:894 [inline]
 udf_map_block+0x1c96/0x5330 fs/udf/inode.c:447
 __udf_get_block+0x122/0x410 fs/udf/inode.c:461
 __block_write_begin_int+0x6c5/0x1e70 fs/buffer.c:2116
 block_write_begin+0x8b/0x120 fs/buffer.c:2226
 udf_write_begin+0x100/0x340 fs/udf/inode.c:256
 generic_perform_write+0x341/0xbd0 mm/filemap.c:4055
 __generic_file_write_iter+0x1b1/0x230 mm/filemap.c:4153
 udf_file_write_iter+0x2f8/0x660 fs/udf/file.c:111
 iter_file_splice_write+0xbd9/0x1510 fs/splice.c:743
 do_splice_from fs/splice.c:941 [inline]
 direct_splice_actor+0x117/0x210 fs/splice.c:1164
 splice_direct_to_actor+0x56f/0xc50 fs/splice.c:1108
 do_splice_direct_actor fs/splice.c:1207 [inline]
 do_splice_direct+0x285/0x3e0 fs/splice.c:1233
 do_sendfile+0x560/0x8a0 fs/read_write.c:1363
 __do_sys_sendfile64 fs/read_write.c:1424 [inline]
 __se_sys_sendfile64+0x178/0x1e0 fs/read_write.c:1410
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x7e/0x180 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f6e4c37ff19
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:00007f6e4d1f7058 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007f6e4c545fa0 RCX: 00007f6e4c37ff19
RDX: 0000000000000000 RSI: 0000000000000005 RDI: 0000000000000005
RBP: 00007f6e4c3f3986 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000800000009 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f6e4c545fa0 R15: 00007ffeb3bbdef8
 </TASK>