[PATCH] ecryptfs: remove unneeded buggy code in ecryptfs_do_create()

[PATCH] ecryptfs: remove unneeded buggy code in ecryptfs_do_create()

[Alexey Khoroshilov]

There is a bug in error handling of lock_parent() in ecryptfs_do_create():
lock_parent() acquries mutex even if dget_parent() fails, so mutex should be unlocked anyway.

But dget_parent() does not fail, so the patch just removes unneeded buggy code.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
---
 fs/ecryptfs/inode.c | 7 -------
 1 file changed, 7 deletions(-)

diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
index d4a9431ec73c..97735c75085f 100644
--- a/fs/ecryptfs/inode.c
+++ b/fs/ecryptfs/inode.c
@@ -192,12 +192,6 @@ ecryptfs_do_create(struct inode *directory_inode,
 
 	lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry);
 	lower_dir_dentry = lock_parent(lower_dentry);
-	if (IS_ERR(lower_dir_dentry)) {
-		ecryptfs_printk(KERN_ERR, "Error locking directory of "
-				"dentry\n");
-		inode = ERR_CAST(lower_dir_dentry);
-		goto out;
-	}
 	rc = vfs_create(lower_dir_dentry->d_inode, lower_dentry, mode, true);
 	if (rc) {
 		printk(KERN_ERR "%s: Failure to create dentry in lower fs; "
@@ -215,7 +209,6 @@ ecryptfs_do_create(struct inode *directory_inode,
 	fsstack_copy_inode_size(directory_inode, lower_dir_dentry->d_inode);
 out_lock:
 	unlock_dir(lower_dir_dentry);
-out:
 	return inode;
 }
 
-- 
1.9.1

Re: [PATCH] ecryptfs: remove unneeded buggy code in ecryptfs_do_create()

[Tyler Hicks]

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Hi Alexey - thanks for the patch.

On 2014-09-23 00:39:31, Alexey Khoroshilov wrote:
> There is a bug in error handling of lock_parent() in ecryptfs_do_create():
> lock_parent() acquries mutex even if dget_parent() fails, so mutex should be unlocked anyway.
> 
> But dget_parent() does not fail, so the patch just removes unneeded buggy code.
> 
> Found by Linux Driver Verification project (linuxtesting.org).
> 
> Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>

This looks good to me and I've included it in the pull request that I
just sent to Linus. Thanks!

Tyler

> ---
>  fs/ecryptfs/inode.c | 7 -------
>  1 file changed, 7 deletions(-)
> 
> diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
> index d4a9431ec73c..97735c75085f 100644
> --- a/fs/ecryptfs/inode.c
> +++ b/fs/ecryptfs/inode.c
> @@ -192,12 +192,6 @@ ecryptfs_do_create(struct inode *directory_inode,
>  
>  	lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry);
>  	lower_dir_dentry = lock_parent(lower_dentry);
> -	if (IS_ERR(lower_dir_dentry)) {
> -		ecryptfs_printk(KERN_ERR, "Error locking directory of "
> -				"dentry\n");
> -		inode = ERR_CAST(lower_dir_dentry);
> -		goto out;
> -	}
>  	rc = vfs_create(lower_dir_dentry->d_inode, lower_dentry, mode, true);
>  	if (rc) {
>  		printk(KERN_ERR "%s: Failure to create dentry in lower fs; "
> @@ -215,7 +209,6 @@ ecryptfs_do_create(struct inode *directory_inode,
>  	fsstack_copy_inode_size(directory_inode, lower_dir_dentry->d_inode);
>  out_lock:
>  	unlock_dir(lower_dir_dentry);
> -out:
>  	return inode;
>  }
>  
> -- 
> 1.9.1
> 

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