ecryptfs: Fix refcnt leak on ecryptfs_follow_link() error path

If ->follow_link handler return the error, it should decrement
nd->path refcnt. But, ecryptfs_follow_link() doesn't decrement.

This patch fix it by using usual nd_set_link() style error handling,
instead of playing with nd->path.

Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 12 insertions, 12 deletions

diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
index 429ca0b3ba08..7f8545032930 100644
--- a/fs/ecryptfs/inode.c
+++ b/fs/ecryptfs/inode.c
@@ -715,31 +715,31 @@ static void *ecryptfs_follow_link(struct dentry *dentry, struct nameidata *nd)
         /* Released in ecryptfs_put_link(); only release here on error */
         buf = kmalloc(len, GFP_KERNEL);
         if (!buf) {
-                rc = -ENOMEM;
+                buf = ERR_PTR(-ENOMEM);
                 goto out;
         }
         old_fs = get_fs();
         set_fs(get_ds());
         rc = dentry->d_inode->i_op->readlink(dentry, (char __user *)buf, len);
         set_fs(old_fs);
-        if (rc < 0)
-                goto out_free;
-        else
+        if (rc < 0) {
+                kfree(buf);
+                buf = ERR_PTR(rc);
+        } else
                 buf[rc] = '\0';
-        rc = 0;
-        nd_set_link(nd, buf);
-        goto out;
-out_free:
-        kfree(buf);
 out:
-        return ERR_PTR(rc);
+        nd_set_link(nd, buf);
+        return NULL;
 }
 
 static void
 ecryptfs_put_link(struct dentry *dentry, struct nameidata *nd, void *ptr)
 {
-        /* Free the char* */
-        kfree(nd_get_link(nd));
+        char *buf = nd_get_link(nd);
+        if (!IS_ERR(buf)) {
+                /* Free the char* */
+                kfree(buf);
+        }
 }
 
 /**