======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.6.763/9575 is trying to acquire lock:
ffff888033dca408 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfsplus_get_block+0x39e/0x1530

but task is already holding lock:
ffff88803194b0f8 (&sbi->alloc_mutex){+.+.}-{4:4}, at: hfsplus_block_allocate+0x94/0x9b0

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&sbi->alloc_mutex){+.+.}-{4:4}:
       lock_acquire+0x120/0x360
       __mutex_lock+0x187/0x1350
       hfsplus_block_allocate+0x94/0x9b0
       hfsplus_file_extend+0xae3/0x1990
       hfsplus_bmap_reserve+0x122/0x500
       hfsplus_create_cat+0x183/0x1000
       hfsplus_fill_super+0x12f5/0x1b50
       get_tree_bdev_flags+0x40e/0x4d0
       vfs_get_tree+0x92/0x2b0
       do_new_mount+0x302/0x9e0
       __se_sys_mount+0x313/0x410
       do_syscall_64+0xfa/0xfa0
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #0 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{4:4}:
       validate_chain+0xb9b/0x2140
       __lock_acquire+0xab9/0xd20
       lock_acquire+0x120/0x360
       __mutex_lock+0x187/0x1350
       hfsplus_get_block+0x39e/0x1530
       block_read_full_folio+0x29f/0x830
       filemap_read_folio+0x117/0x380
       do_read_cache_folio+0x350/0x590
       read_cache_page+0x5d/0x170
       hfsplus_block_allocate+0xe4/0x9b0
       hfsplus_file_extend+0xae3/0x1990
       hfsplus_get_block+0x411/0x1530
       __block_write_begin_int+0x6b5/0x1900
       cont_write_begin+0x789/0xb50
       hfsplus_write_begin+0x66/0xb0
       generic_perform_write+0x2c5/0x900
       generic_file_write_iter+0x117/0x550
       __kernel_write_iter+0x428/0x910
       __kernel_write+0xef/0x150
       __dump_emit+0x206/0x310
       elf_core_dump+0x2a87/0x3960
       coredump_write+0x116c/0x1900
       vfs_coredump+0x1db5/0x2a60
       get_signal+0x1108/0x1340
       arch_do_signal_or_restart+0xa0/0x790
       irqentry_exit_to_user_mode+0x7e/0x110
       exc_page_fault+0xab/0x100
       asm_exc_page_fault+0x26/0x30

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&sbi->alloc_mutex);
                               lock(&HFSPLUS_I(inode)->extents_lock);
                               lock(&sbi->alloc_mutex);
  lock(&HFSPLUS_I(inode)->extents_lock);

 *** DEADLOCK ***

4 locks held by syz.6.763/9575:
 #0: ffff88810ead2420 (sb_writers#13){.+.+}-{0:0}, at: vfs_coredump+0x1db5/0x2a60
 #1: ffff88812ed8baf8 (&sb->s_type->i_mutex_key#21){+.+.}-{4:4}, at: generic_file_write_iter+0xeb/0x550
 #2: ffff88812ed8b908 (&hip->extents_lock){+.+.}-{4:4}, at: hfsplus_file_extend+0x1fc/0x1990
 #3: ffff88803194b0f8 (&sbi->alloc_mutex){+.+.}-{4:4}, at: hfsplus_block_allocate+0x94/0x9b0

stack backtrace:
CPU: 1 UID: 0 PID: 9575 Comm: syz.6.763 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250
 print_circular_bug+0x2ee/0x310
 check_noncircular+0x134/0x160
 validate_chain+0xb9b/0x2140
 __lock_acquire+0xab9/0xd20
 lock_acquire+0x120/0x360
 __mutex_lock+0x187/0x1350
 hfsplus_get_block+0x39e/0x1530
 block_read_full_folio+0x29f/0x830
 filemap_read_folio+0x117/0x380
 do_read_cache_folio+0x350/0x590
 read_cache_page+0x5d/0x170
 hfsplus_block_allocate+0xe4/0x9b0
 hfsplus_file_extend+0xae3/0x1990
 hfsplus_get_block+0x411/0x1530
 __block_write_begin_int+0x6b5/0x1900
 cont_write_begin+0x789/0xb50
 hfsplus_write_begin+0x66/0xb0
 generic_perform_write+0x2c5/0x900
 generic_file_write_iter+0x117/0x550
 __kernel_write_iter+0x428/0x910
 __kernel_write+0xef/0x150
 __dump_emit+0x206/0x310
 elf_core_dump+0x2a87/0x3960
 coredump_write+0x116c/0x1900
 vfs_coredump+0x1db5/0x2a60
 get_signal+0x1108/0x1340
 arch_do_signal_or_restart+0xa0/0x790
 irqentry_exit_to_user_mode+0x7e/0x110
 exc_page_fault+0xab/0x100
 asm_exc_page_fault+0x26/0x30
RIP: 0033:0x7fd72f38ec31
Code: 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 83 c8 ff c3 66 2e 0f 1f
RSP: 002b:fffffffffffffea0 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007fd72f5d5fa0 RCX: 00007fd72f38ec29
RDX: 0000000000000000 RSI: fffffffffffffea0 RDI: 0000000000000000
RBP: 00007fd72f411e41 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd72f5d6038 R14: 00007fd72f5d5fa0 R15: 00007fff12fc8ce8
 </TASK>
syz.6.763 (9575) used greatest stack depth: 18536 bytes left
