syzbot

======================================================
WARNING: possible circular locking dependency detected
5.15.180-syzkaller #0 Not tainted
------------------------------------------------------
syz.2.208/5135 is trying to acquire lock:
ffff88805d2f0df8 (&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:
ffff88807ea1a0b0 (&tree->tree_lock/1){+.+.}-{3:3}, at: hfs_find_init+0x16a/0x1e0 fs/hfs/bfind.c:-1

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&tree->tree_lock/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 fs/hfs/bfind.c:-1
       hfs_ext_read_extent fs/hfs/extent.c:200 [inline]
       hfs_extend_file+0x317/0x1440 fs/hfs/extent.c:401
       hfs_bmap_reserve+0xd5/0x3f0 fs/hfs/btree.c:231
       hfs_cat_create+0x1e7/0xa60 fs/hfs/catalog.c:104
       hfs_create+0x62/0xd0 fs/hfs/dir.c:202
       lookup_open fs/namei.c:3462 [inline]
       open_last_lookups fs/namei.c:3532 [inline]
       path_openat+0x130a/0x2f20 fs/namei.c:3739
       do_filp_open+0x21c/0x460 fs/namei.c:3769
       do_sys_openat2+0x13b/0x4f0 fs/open.c:1253
       do_sys_open fs/open.c:1269 [inline]
       __do_sys_openat fs/open.c:1285 [inline]
       __se_sys_openat fs/open.c:1280 [inline]
       __x64_sys_openat+0x243/0x290 fs/open.c:1280
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x3b/0x80 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:2172 [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/0x80 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/1);
                               lock(&HFS_I(tree->inode)->extents_lock);
                               lock(&tree->tree_lock/1);
  lock(&HFS_I(tree->inode)->extents_lock);

 *** DEADLOCK ***

5 locks held by syz.2.208/5135:
 #0: ffff88801f4159f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2cb/0x380 fs/file.c:1058
 #1: ffff88807ea18460 (sb_writers#17){.+.+}-{0:0}, at: vfs_write+0x29a/0xe50 fs/read_write.c:590
 #2: ffff88805d2f2328 (&sb->s_type->i_mutex_key#24){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline]
 #2: ffff88805d2f2328 (&sb->s_type->i_mutex_key#24){+.+.}-{3:3}, at: generic_file_write_iter+0x7c/0x1b0 mm/filemap.c:3941
 #3: ffff88805d2f2178 (&HFS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfs_extend_file+0xfb/0x1440 fs/hfs/extent.c:397
 #4: ffff88807ea1a0b0 (&tree->tree_lock/1){+.+.}-{3:3}, at: hfs_find_init+0x16a/0x1e0 fs/hfs/bfind.c:-1

stack backtrace:
CPU: 0 PID: 5135 Comm: syz.2.208 Not tainted 5.15.180-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
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:2172 [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/0x80 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fbf27042169
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:00007fbf24eaa038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fbf27269fa0 RCX: 00007fbf27042169
RDX: 000000000208e24b RSI: 0000200000000000 RDI: 0000000000000004
RBP: 00007fbf270c4a68 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fbf27269fa0 R15: 00007ffef4d41fb8
 </TASK>