syzbot

memfd_create() without MFD_EXEC nor MFD_NOEXEC_SEAL, pid=4997 'syz-executor722'
loop0: detected capacity change from 0 to 1024
============================================
WARNING: possible recursive locking detected
6.4.0-rc4-syzkaller-00268-g51f269a6ecc7 #0 Not tainted
--------------------------------------------
syz-executor722/4997 is trying to acquire lock:
ffff888076ab80b0 (&tree->tree_lock/1){+.+.}-{3:3}, at: hfsplus_find_init+0x14a/0x1c0

but task is already holding lock:
ffff888076ab80b0 (&tree->tree_lock/1){+.+.}-{3:3}, at: hfsplus_find_init+0x14a/0x1c0

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

       CPU0
       ----
  lock(&tree->tree_lock/1);
  lock(&tree->tree_lock/1);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

5 locks held by syz-executor722/4997:
 #0: ffff88807e236460 (sb_writers#9){.+.+}-{0:0}, at: vfs_write+0x223/0xb20 fs/read_write.c:580
 #1: ffff888076a924c0 (&sb->s_type->i_mutex_key#14){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:775 [inline]
 #1: ffff888076a924c0 (&sb->s_type->i_mutex_key#14){+.+.}-{3:3}, at: generic_file_write_iter+0x83/0x310 mm/filemap.c:4080
 #2: ffff888076a922c8 (&hip->extents_lock){+.+.}-{3:3}, at: hfsplus_file_extend+0x1d6/0x1b10 fs/hfsplus/extents.c:457
 #3: ffff888076ab80b0 (&tree->tree_lock/1){+.+.}-{3:3}, at: hfsplus_find_init+0x14a/0x1c0
 #4: ffff888076a90108 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfsplus_file_extend+0x1d6/0x1b10 fs/hfsplus/extents.c:457

stack backtrace:
CPU: 0 PID: 4997 Comm: syz-executor722 Not tainted 6.4.0-rc4-syzkaller-00268-g51f269a6ecc7 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/25/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106
 print_deadlock_bug kernel/locking/lockdep.c:3006 [inline]
 check_deadlock kernel/locking/lockdep.c:3049 [inline]
 validate_chain+0x473a/0x58f0 kernel/locking/lockdep.c:3834
 __lock_acquire+0x1316/0x2070 kernel/locking/lockdep.c:5088
 lock_acquire+0x1e3/0x520 kernel/locking/lockdep.c:5705
 __mutex_lock_common+0x1d8/0x2530 kernel/locking/mutex.c:603
 __mutex_lock kernel/locking/mutex.c:747 [inline]
 mutex_lock_nested+0x1b/0x20 kernel/locking/mutex.c:799
 hfsplus_find_init+0x14a/0x1c0
 hfsplus_ext_read_extent fs/hfsplus/extents.c:216 [inline]
 hfsplus_file_extend+0x40e/0x1b10 fs/hfsplus/extents.c:461
 hfsplus_bmap_reserve+0x105/0x4e0 fs/hfsplus/btree.c:358
 __hfsplus_ext_write_extent+0x2a4/0x5b0 fs/hfsplus/extents.c:104
 __hfsplus_ext_cache_extent+0x84/0xe00 fs/hfsplus/extents.c:186
 hfsplus_ext_read_extent fs/hfsplus/extents.c:218 [inline]
 hfsplus_file_extend+0x439/0x1b10 fs/hfsplus/extents.c:461
 hfsplus_get_block+0x406/0x14e0 fs/hfsplus/extents.c:245
 __block_write_begin_int+0x548/0x1a50 fs/buffer.c:2064
 __block_write_begin fs/buffer.c:2114 [inline]
 block_write_begin+0x9c/0x1f0 fs/buffer.c:2175
 cont_write_begin+0x643/0x880 fs/buffer.c:2534
 hfsplus_write_begin+0x8a/0xd0 fs/hfsplus/inode.c:52
 generic_perform_write+0x300/0x5e0 mm/filemap.c:3923
 __generic_file_write_iter+0x17a/0x400 mm/filemap.c:4051
 generic_file_write_iter+0xaf/0x310 mm/filemap.c:4083
 call_write_iter include/linux/fs.h:1868 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x790/0xb20 fs/read_write.c:584
 ksys_write+0x1a0/0x2c0 fs/read_write.c:637
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f4e22ea27d9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 51 14 00 00 90 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 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fffd2f08ec8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f4e22ea27d9
RDX: 00000000fffffff0 RSI: 0000000020004200 RDI: 0000000000000004
RBP: 00007f4e22e62070 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000647 R11: 0000000000000246 R12: 00007f4e22e62100
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>