syzbot

loop3: detected capacity change from 0 to 1024
======================================================
WARNING: possible circular locking dependency detected
6.1.84-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor.3/19673 is trying to acquire lock:
ffff88805177c0f8 (&sbi->alloc_mutex){+.+.}-{3:3}, at: hfsplus_block_allocate+0x9a/0x8b0 fs/hfsplus/bitmap.c:35

but task is already holding lock:
ffff88807c978108 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfsplus_file_extend+0x1d2/0x1b10 fs/hfsplus/extents.c:457

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}:
       lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
       __mutex_lock_common kernel/locking/mutex.c:603 [inline]
       __mutex_lock+0x132/0xd80 kernel/locking/mutex.c:747
       hfsplus_get_block+0x37f/0x14e0 fs/hfsplus/extents.c:260
       block_read_full_folio+0x403/0xf60 fs/buffer.c:2271
       filemap_read_folio+0x199/0x780 mm/filemap.c:2461
       do_read_cache_folio+0x2ee/0x810 mm/filemap.c:3598
       do_read_cache_page+0x32/0x220 mm/filemap.c:3640
       read_mapping_page include/linux/pagemap.h:791 [inline]
       hfsplus_block_allocate+0xea/0x8b0 fs/hfsplus/bitmap.c:37
       hfsplus_file_extend+0xa4c/0x1b10 fs/hfsplus/extents.c:468
       hfsplus_get_block+0x402/0x14e0 fs/hfsplus/extents.c:245
       __block_write_begin_int+0x544/0x1a30 fs/buffer.c:1991
       __block_write_begin fs/buffer.c:2041 [inline]
       block_write_begin+0x98/0x1f0 fs/buffer.c:2102
       cont_write_begin+0x63f/0x880 fs/buffer.c:2456
       hfsplus_write_begin+0x86/0xd0 fs/hfsplus/inode.c:52
       page_symlink+0x2c1/0x4e0 fs/namei.c:5220
       hfsplus_symlink+0xc6/0x260 fs/hfsplus/dir.c:449
       vfs_symlink+0x247/0x3d0 fs/namei.c:4473
       do_symlinkat+0x21e/0x390 fs/namei.c:4502
       __do_sys_symlinkat fs/namei.c:4519 [inline]
       __se_sys_symlinkat fs/namei.c:4516 [inline]
       __x64_sys_symlinkat+0x95/0xa0 fs/namei.c:4516
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:81
       entry_SYSCALL_64_after_hwframe+0x63/0xcd

-> #0 (&sbi->alloc_mutex){+.+.}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3090 [inline]
       check_prevs_add kernel/locking/lockdep.c:3209 [inline]
       validate_chain+0x1661/0x5950 kernel/locking/lockdep.c:3825
       __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049
       lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
       __mutex_lock_common kernel/locking/mutex.c:603 [inline]
       __mutex_lock+0x132/0xd80 kernel/locking/mutex.c:747
       hfsplus_block_allocate+0x9a/0x8b0 fs/hfsplus/bitmap.c:35
       hfsplus_file_extend+0xa4c/0x1b10 fs/hfsplus/extents.c:468
       hfsplus_bmap_reserve+0x101/0x4e0 fs/hfsplus/btree.c:358
       hfsplus_create_cat+0x1a9/0x1ba0 fs/hfsplus/catalog.c:272
       hfsplus_fill_super+0x13e6/0x1c90 fs/hfsplus/super.c:560
       mount_bdev+0x2c9/0x3f0 fs/super.c:1432
       legacy_get_tree+0xeb/0x180 fs/fs_context.c:632
       vfs_get_tree+0x88/0x270 fs/super.c:1562
       do_new_mount+0x2ba/0xb40 fs/namespace.c:3051
       do_mount fs/namespace.c:3394 [inline]
       __do_sys_mount fs/namespace.c:3602 [inline]
       __se_sys_mount+0x2d5/0x3c0 fs/namespace.c:3579
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:81
       entry_SYSCALL_64_after_hwframe+0x63/0xcd

other info that might help us debug this:

 Possible unsafe locking scenario:

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

 *** DEADLOCK ***

4 locks held by syz-executor.3/19673:
 #0: ffff8880764e40e0 (&type->s_umount_key#92/1){+.+.}-{3:3}, at: alloc_super+0x217/0x930 fs/super.c:228
 #1: ffff88805177c198 (&sbi->vh_mutex){+.+.}-{3:3}, at: hfsplus_fill_super+0x1378/0x1c90 fs/hfsplus/super.c:553
 #2: ffff88805f0020b0 (&tree->tree_lock#2){+.+.}-{3:3}, at: hfsplus_find_init+0x146/0x1c0
 #3: ffff88807c978108 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfsplus_file_extend+0x1d2/0x1b10 fs/hfsplus/extents.c:457

stack backtrace:
CPU: 1 PID: 19673 Comm: syz-executor.3 Not tainted 6.1.84-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 check_noncircular+0x2fa/0x3b0 kernel/locking/lockdep.c:2170
 check_prev_add kernel/locking/lockdep.c:3090 [inline]
 check_prevs_add kernel/locking/lockdep.c:3209 [inline]
 validate_chain+0x1661/0x5950 kernel/locking/lockdep.c:3825
 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049
 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
 __mutex_lock_common kernel/locking/mutex.c:603 [inline]
 __mutex_lock+0x132/0xd80 kernel/locking/mutex.c:747
 hfsplus_block_allocate+0x9a/0x8b0 fs/hfsplus/bitmap.c:35
 hfsplus_file_extend+0xa4c/0x1b10 fs/hfsplus/extents.c:468
 hfsplus_bmap_reserve+0x101/0x4e0 fs/hfsplus/btree.c:358
 hfsplus_create_cat+0x1a9/0x1ba0 fs/hfsplus/catalog.c:272
 hfsplus_fill_super+0x13e6/0x1c90 fs/hfsplus/super.c:560
 mount_bdev+0x2c9/0x3f0 fs/super.c:1432
 legacy_get_tree+0xeb/0x180 fs/fs_context.c:632
 vfs_get_tree+0x88/0x270 fs/super.c:1562
 do_new_mount+0x2ba/0xb40 fs/namespace.c:3051
 do_mount fs/namespace.c:3394 [inline]
 __do_sys_mount fs/namespace.c:3602 [inline]
 __se_sys_mount+0x2d5/0x3c0 fs/namespace.c:3579
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f436047f56a
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 09 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f435eff5ef8 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f435eff5f80 RCX: 00007f436047f56a
RDX: 0000000020000000 RSI: 0000000020002380 RDI: 00007f435eff5f40
RBP: 0000000020000000 R08: 00007f435eff5f80 R09: 000000000080000c
R10: 000000000080000c R11: 0000000000000202 R12: 0000000020002380
R13: 00007f435eff5f40 R14: 00000000000006da R15: 00000000200023c0
 </TASK>