[PATCH] fs, ext4: Fix potential memory leak in ext4_fill_super

[PATCH] fs, ext4: Fix potential memory leak in ext4_fill_super

[Cyrill Gorcunov]

Under heavy memory pressure we may hit out of memory
situation and as result kstrdup'ed options will not be
freed. Fix it.

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
---
 fs/ext4/super.c |    8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

Index: linux-2.6.git/fs/ext4/super.c
=====================================================================
--- linux-2.6.git.orig/fs/ext4/super.c
+++ linux-2.6.git/fs/ext4/super.c
@@ -2448,7 +2448,7 @@ static int ext4_fill_super(struct super_
 	struct inode *root;
 	char *cp;
 	const char *descr;
-	int ret = -EINVAL;
+	int ret = -ENOMEM;
 	int blocksize;
 	unsigned int db_count;
 	unsigned int i;
@@ -2459,13 +2459,13 @@ static int ext4_fill_super(struct super_
 
 	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
 	if (!sbi)
-		return -ENOMEM;
+		goto out_free_orig;
 
 	sbi->s_blockgroup_lock =
 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
 	if (!sbi->s_blockgroup_lock) {
 		kfree(sbi);
-		return -ENOMEM;
+		goto out_free_orig;
 	}
 	sb->s_fs_info = sbi;
 	sbi->s_mount_opt = 0;
@@ -2482,6 +2482,7 @@ static int ext4_fill_super(struct super_
 	for (cp = sb->s_id; (cp = strchr(cp, '/'));)
 		*cp = '!';
 
+	ret = -EINVAL;
 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
 	if (!blocksize) {
 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
@@ -3093,6 +3094,7 @@ out_fail:
 	kfree(sbi->s_blockgroup_lock);
 	kfree(sbi);
 	lock_kernel();
+out_free_orig:
 	kfree(orig_data);
 	return ret;
 }

Re: [PATCH] fs, ext4: Fix potential memory leak in ext4_fill_super

[Ted Ts'o]

On Wed, Jun 16, 2010 at 07:33:32PM +0400, Cyrill Gorcunov wrote:
> Under heavy memory pressure we may hit out of memory
> situation and as result kstrdup'ed options will not be
> freed. Fix it.
> 
> Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>

Thanks, I've added this to the ext4 tree.

						- Ted