[PATCH] cachefiles: Fix double unlock in nomem_d_alloc error path

Hongling Zeng posted 1 patch 5 days, 21 hours ago
fs/cachefiles/namei.c | 1 -
1 file changed, 1 deletion(-)
[PATCH] cachefiles: Fix double unlock in nomem_d_alloc error path
Posted by Hongling Zeng 5 days, 21 hours ago
When start_creating() fails and returns -ENOMEM, it has already
released the parent directory lock in __start_dirop():

    static struct dentry *__start_dirop(...)
    {
        ...
        inode_lock_nested(dir, I_MUTEX_PARENT);
        dentry = lookup_one_qstr_excl(name, parent, lookup_flags);
        if (IS_ERR(dentry))
            inode_unlock(dir);  <-- Lock released on error
        return dentry;
    }

However, the nomem_d_alloc error path in cachefiles_get_directory()
unconditionally calls inode_unlock(d_inode(dir)) again, causing a
double unlock that corrupts the rwsem state.

This is a leftover from commit 7ab96df840e60 which replaced manual
locking with start_creating() but failed to update the nomem_d_alloc
path (while correctly updating mkdir_error and lookup_error paths).

Fixes: 7ab96df840e6 ("VFS/nfsd/cachefiles/ovl: add start_creating() and end_creating()")
Signed-off-by: Hongling Zeng <zenghongling@kylinos.cn>
---
 fs/cachefiles/namei.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/fs/cachefiles/namei.c b/fs/cachefiles/namei.c
index 2937db690b40..2c46f0decb02 100644
--- a/fs/cachefiles/namei.c
+++ b/fs/cachefiles/namei.c
@@ -209,7 +209,6 @@ struct dentry *cachefiles_get_directory(struct cachefiles_cache *cache,
 	return ERR_PTR(ret);
 
 nomem_d_alloc:
-	inode_unlock(d_inode(dir));
 	_leave(" = -ENOMEM");
 	return ERR_PTR(-ENOMEM);
 }
-- 
2.25.1