syzbot

loop6: detected capacity change from 0 to 64
======================================================
WARNING: possible circular locking dependency detected
5.15.177-syzkaller #0 Not tainted
------------------------------------------------------
syz.6.723/7875 is trying to acquire lock:
ffff88802b082e78 (&HFS_I(tree->inode)->extents_lock){+.+.}-{3:3}, at: hfs_extend_file+0xfb/0x1440 fs/hfs/extent.c:397

but task is already holding lock:
ffff88801fd540b0 (&tree->tree_lock#2/1){+.+.}-{3:3}, at: hfs_find_init+0x16a/0x1e0

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&tree->tree_lock#2/1){+.+.}-{3:3}:
       lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
       __mutex_lock_common+0x1da/0x25a0 kernel/locking/mutex.c:596
       __mutex_lock kernel/locking/mutex.c:729 [inline]
       mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
       hfs_find_init+0x16a/0x1e0
       hfs_ext_read_extent fs/hfs/extent.c:200 [inline]
       hfs_get_block+0x4f0/0xb60 fs/hfs/extent.c:366
       block_read_full_page+0x2f9/0xde0 fs/buffer.c:2290
       do_read_cache_page+0x752/0x1040
       read_mapping_page include/linux/pagemap.h:515 [inline]
       __hfs_bnode_create+0x4e2/0xba0 fs/hfs/bnode.c:297
       hfs_bnode_find+0x21f/0xe10 fs/hfs/bnode.c:346
       hfs_brec_find+0x179/0x570 fs/hfs/bfind.c:126
       hfs_brec_read+0x20/0x100 fs/hfs/bfind.c:165
       hfs_cat_find_brec+0x151/0x470 fs/hfs/catalog.c:194
       hfs_fill_super+0x10c6/0x1790 fs/hfs/super.c:419
       mount_bdev+0x2c9/0x3f0 fs/super.c:1400
       legacy_get_tree+0xeb/0x180 fs/fs_context.c:611
       vfs_get_tree+0x88/0x270 fs/super.c:1530
       do_new_mount+0x2ba/0xb40 fs/namespace.c:3012
       do_mount fs/namespace.c:3355 [inline]
       __do_sys_mount fs/namespace.c:3563 [inline]
       __se_sys_mount+0x2d5/0x3c0 fs/namespace.c:3540
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x66/0xd0

-> #0 (&HFS_I(tree->inode)->extents_lock){+.+.}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3053 [inline]
       check_prevs_add kernel/locking/lockdep.c:3172 [inline]
       validate_chain+0x1649/0x5930 kernel/locking/lockdep.c:3788
       __lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5012
       lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
       __mutex_lock_common+0x1da/0x25a0 kernel/locking/mutex.c:596
       __mutex_lock kernel/locking/mutex.c:729 [inline]
       mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
       hfs_extend_file+0xfb/0x1440 fs/hfs/extent.c:397
       hfs_bmap_reserve+0xd5/0x3f0 fs/hfs/btree.c:231
       __hfs_ext_write_extent+0x22e/0x4f0 fs/hfs/extent.c:121
       __hfs_ext_cache_extent+0x6a/0x990 fs/hfs/extent.c:174
       hfs_ext_read_extent fs/hfs/extent.c:202 [inline]
       hfs_extend_file+0x340/0x1440 fs/hfs/extent.c:401
       hfs_get_block+0x3e0/0xb60 fs/hfs/extent.c:353
       __block_write_begin_int+0x60b/0x1650 fs/buffer.c:2012
       __block_write_begin fs/buffer.c:2062 [inline]
       block_write_begin fs/buffer.c:2122 [inline]
       cont_write_begin+0x5d6/0x840 fs/buffer.c:2471
       hfs_write_begin+0x92/0xd0 fs/hfs/inode.c:59
       generic_perform_write+0x2bf/0x5b0 mm/filemap.c:3785
       __generic_file_write_iter+0x243/0x4f0 mm/filemap.c:3912
       generic_file_write_iter+0xa7/0x1b0 mm/filemap.c:3944
       call_write_iter include/linux/fs.h:2174 [inline]
       new_sync_write fs/read_write.c:507 [inline]
       vfs_write+0xacd/0xe50 fs/read_write.c:594
       ksys_write+0x1a2/0x2c0 fs/read_write.c:647
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x66/0xd0

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&tree->tree_lock#2/1);
                               lock(&HFS_I(tree->inode)->extents_lock);
                               lock(&tree->tree_lock#2/1);
  lock(&HFS_I(tree->inode)->extents_lock);

 *** DEADLOCK ***

5 locks held by syz.6.723/7875:
 #0: ffff88807874d270 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2cb/0x380 fs/file.c:1058
 #1: ffff8880517d4460 (sb_writers#32){.+.+}-{0:0}, at: vfs_write+0x29a/0xe50 fs/read_write.c:590
 #2: ffff88802b0843a8 (&sb->s_type->i_mutex_key#39){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:789 [inline]
 #2: ffff88802b0843a8 (&sb->s_type->i_mutex_key#39){+.+.}-{3:3}, at: generic_file_write_iter+0x7c/0x1b0 mm/filemap.c:3941
 #3: ffff88802b0841f8 (&HFS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfs_extend_file+0xfb/0x1440 fs/hfs/extent.c:397
 #4: ffff88801fd540b0 (&tree->tree_lock#2/1){+.+.}-{3:3}, at: hfs_find_init+0x16a/0x1e0

stack backtrace:
CPU: 1 PID: 7875 Comm: syz.6.723 Not tainted 5.15.177-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106
 check_noncircular+0x2f8/0x3b0 kernel/locking/lockdep.c:2133
 check_prev_add kernel/locking/lockdep.c:3053 [inline]
 check_prevs_add kernel/locking/lockdep.c:3172 [inline]
 validate_chain+0x1649/0x5930 kernel/locking/lockdep.c:3788
 __lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5012
 lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
 __mutex_lock_common+0x1da/0x25a0 kernel/locking/mutex.c:596
 __mutex_lock kernel/locking/mutex.c:729 [inline]
 mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
 hfs_extend_file+0xfb/0x1440 fs/hfs/extent.c:397
 hfs_bmap_reserve+0xd5/0x3f0 fs/hfs/btree.c:231
 __hfs_ext_write_extent+0x22e/0x4f0 fs/hfs/extent.c:121
 __hfs_ext_cache_extent+0x6a/0x990 fs/hfs/extent.c:174
 hfs_ext_read_extent fs/hfs/extent.c:202 [inline]
 hfs_extend_file+0x340/0x1440 fs/hfs/extent.c:401
 hfs_get_block+0x3e0/0xb60 fs/hfs/extent.c:353
 __block_write_begin_int+0x60b/0x1650 fs/buffer.c:2012
 __block_write_begin fs/buffer.c:2062 [inline]
 block_write_begin fs/buffer.c:2122 [inline]
 cont_write_begin+0x5d6/0x840 fs/buffer.c:2471
 hfs_write_begin+0x92/0xd0 fs/hfs/inode.c:59
 generic_perform_write+0x2bf/0x5b0 mm/filemap.c:3785
 __generic_file_write_iter+0x243/0x4f0 mm/filemap.c:3912
 generic_file_write_iter+0xa7/0x1b0 mm/filemap.c:3944
 call_write_iter include/linux/fs.h:2174 [inline]
 new_sync_write fs/read_write.c:507 [inline]
 vfs_write+0xacd/0xe50 fs/read_write.c:594
 ksys_write+0x1a2/0x2c0 fs/read_write.c:647
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f927a08bd29
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:00007f9277ef5038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f927a2a4fa0 RCX: 00007f927a08bd29
RDX: 000000000000fea7 RSI: 0000000020000000 RDI: 0000000000000006
RBP: 00007f927a10d2a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f927a2a4fa0 R15: 00007ffcf0b01948
 </TASK>