[PATCH] ramfs: Fix memory leak on ramfs_fill_super error paths

[PATCH] ramfs: Fix memory leak on ramfs_fill_super error paths

[Axel Lin]

The memory leak was introduced by commit 318ceed0884
"tidy up after d_make_root() conversion".

Signed-off-by: Axel Lin <axel.lin@ingics.com>
---
 fs/ramfs/inode.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/fs/ramfs/inode.c b/fs/ramfs/inode.c
index 39d1465..868a41e 100644
--- a/fs/ramfs/inode.c
+++ b/fs/ramfs/inode.c
@@ -221,7 +221,7 @@ int ramfs_fill_super(struct super_block *sb, void *data, int silent)
 
 	err = ramfs_parse_options(data, &fsi->mount_opts);
 	if (err)
-		return err;
+		goto fail;
 
 	sb->s_maxbytes		= MAX_LFS_FILESIZE;
 	sb->s_blocksize		= PAGE_CACHE_SIZE;
@@ -232,10 +232,16 @@ int ramfs_fill_super(struct super_block *sb, void *data, int silent)
 
 	inode = ramfs_get_inode(sb, NULL, S_IFDIR | fsi->mount_opts.mode, 0);
 	sb->s_root = d_make_root(inode);
-	if (!sb->s_root)
-		return -ENOMEM;
+	if (!sb->s_root) {
+		err = -ENOMEM;
+		goto fail;
+	}
 
 	return 0;
+fail:
+	kfree(fsi);
+	sb->s_fs_info = NULL;
+	return err;
 }
 
 struct dentry *ramfs_mount(struct file_system_type *fs_type,
-- 
1.8.1.2

Re: [PATCH] ramfs: Fix memory leak on ramfs_fill_super error paths

[Kirill A. Shutemov]

On Thu, Nov 14, 2013 at 02:59:19PM +0800, Axel Lin wrote:
> The memory leak was introduced by commit 318ceed0884
> "tidy up after d_make_root() conversion".
> 
> Signed-off-by: Axel Lin <axel.lin@ingics.com>
> ---
>  fs/ramfs/inode.c | 12 +++++++++---
>  1 file changed, 9 insertions(+), 3 deletions(-)
> 
> diff --git a/fs/ramfs/inode.c b/fs/ramfs/inode.c
> index 39d1465..868a41e 100644
> --- a/fs/ramfs/inode.c
> +++ b/fs/ramfs/inode.c
> @@ -221,7 +221,7 @@ int ramfs_fill_super(struct super_block *sb, void *data, int silent)
>  
>  	err = ramfs_parse_options(data, &fsi->mount_opts);
>  	if (err)
> -		return err;
> +		goto fail;
>  
>  	sb->s_maxbytes		= MAX_LFS_FILESIZE;
>  	sb->s_blocksize		= PAGE_CACHE_SIZE;
> @@ -232,10 +232,16 @@ int ramfs_fill_super(struct super_block *sb, void *data, int silent)
>  
>  	inode = ramfs_get_inode(sb, NULL, S_IFDIR | fsi->mount_opts.mode, 0);
>  	sb->s_root = d_make_root(inode);
> -	if (!sb->s_root)
> -		return -ENOMEM;
> +	if (!sb->s_root) {
> +		err = -ENOMEM;
> +		goto fail;
> +	}
>  
>  	return 0;
> +fail:
> +	kfree(fsi);
> +	sb->s_fs_info = NULL;

Why do we need this?
mount_nodev() seems just drop super block if filler fails.

> +	return err;
>  }
>  
>  struct dentry *ramfs_mount(struct file_system_type *fs_type,
-- 
 Kirill A. Shutemov

Re: [PATCH] ramfs: Fix memory leak on ramfs_fill_super error paths

[Al Viro]

On Thu, Nov 14, 2013 at 02:59:19PM +0800, Axel Lin wrote:
> The memory leak was introduced by commit 318ceed0884
> "tidy up after d_make_root() conversion".

No memory leaks there.  Note that ->kill_sb() is called in *all*
cases, so that kfree() will be done by it just fine.

It's *not* ->put_super() - that would've been called only for superblocks
that had passed mount.  ->kill_sb() is called for *all* of them and
that often simplifies cleanup on failure exits quite nicely.