syzbot

memfd_create() without MFD_EXEC nor MFD_NOEXEC_SEAL, pid=4990 'syz-executor546'
loop0: detected capacity change from 0 to 1024
hfsplus: xattr searching failed
hfsplus: xattr searching failed
hfsplus: xattr searching failed
hfsplus: xattr searching failed
============================================
WARNING: possible recursive locking detected
6.4.0-rc4-syzkaller-00051-g48b1320a674e #0 Not tainted
--------------------------------------------
syz-executor546/4990 is trying to acquire lock:
ffff88807c4b1548 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfsplus_get_block+0x383/0x14e0 fs/hfsplus/extents.c:260

but task is already holding lock:
ffff88807c4b2988 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfsplus_file_truncate+0x2da/0xb40 fs/hfsplus/extents.c:576

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

       CPU0
       ----
  lock(&HFSPLUS_I(inode)->extents_lock);
  lock(&HFSPLUS_I(inode)->extents_lock);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

4 locks held by syz-executor546/4990:
 #0: ffff888019650460 (sb_writers#9){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:394
 #1: ffff88807c4b2b80 (&sb->s_type->i_mutex_key#14){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:775 [inline]
 #1: ffff88807c4b2b80 (&sb->s_type->i_mutex_key#14){+.+.}-{3:3}, at: do_truncate+0x20c/0x300 fs/open.c:64
 #2: ffff88807c4b2988 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfsplus_file_truncate+0x2da/0xb40 fs/hfsplus/extents.c:576
 #3: ffff88807e2ec8f8 (&sbi->alloc_mutex){+.+.}-{3:3}, at: hfsplus_block_free+0xbb/0x4d0 fs/hfsplus/bitmap.c:182

stack backtrace:
CPU: 1 PID: 4990 Comm: syz-executor546 Not tainted 6.4.0-rc4-syzkaller-00051-g48b1320a674e #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_get_block+0x383/0x14e0 fs/hfsplus/extents.c:260
 block_read_full_folio+0x47b/0x1000 fs/buffer.c:2349
 filemap_read_folio+0x19d/0x7a0 mm/filemap.c:2421
 do_read_cache_folio+0x134/0x820 mm/filemap.c:3680
 do_read_cache_page+0x32/0x220 mm/filemap.c:3746
 read_mapping_page include/linux/pagemap.h:772 [inline]
 hfsplus_block_free+0x128/0x4d0 fs/hfsplus/bitmap.c:185
 hfsplus_free_extents+0x17a/0xae0 fs/hfsplus/extents.c:363
 hfsplus_file_truncate+0x7d0/0xb40 fs/hfsplus/extents.c:591
 hfsplus_setattr+0x1bd/0x280 fs/hfsplus/inode.c:269
 notify_change+0xc8b/0xf40 fs/attr.c:483
 do_truncate+0x220/0x300 fs/open.c:66
 handle_truncate fs/namei.c:3295 [inline]
 do_open fs/namei.c:3640 [inline]
 path_openat+0x294e/0x3170 fs/namei.c:3791
 do_filp_open+0x234/0x490 fs/namei.c:3818
 do_sys_openat2+0x13f/0x500 fs/open.c:1356
 do_sys_open fs/open.c:1372 [inline]
 __do_sys_creat fs/open.c:1448 [inline]
 __se_sys_creat fs/open.c:1442 [inline]
 __x64_sys_creat+0x123/0x160 fs/open.c:1442
 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: 0033:0x7fc92175a789
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:00007ffe9d0a1b88 EFLAGS: 00000246 ORIG_RAX: 0000000000000055
RAX: ffffffffffffffda RBX: 0032656c69662f2e RCX: 00007fc92175a789