ext2: ensure fast symlinks are NUL-terminated

Ensure fast symlink targets are NUL-terminated, even if corrupted
on-disk.

Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Duane Griffin <duaneg@dghda.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 5 insertions, 2 deletions

diff --git a/fs/ext2/inode.c b/fs/ext2/inode.c
index 7658b33e2653..02b39a5deb74 100644
--- a/fs/ext2/inode.c
+++ b/fs/ext2/inode.c
@@ -32,6 +32,7 @@
 #include <linux/buffer_head.h>
 #include <linux/mpage.h>
 #include <linux/fiemap.h>
+#include <linux/namei.h>
 #include "ext2.h"
 #include "acl.h"
 #include "xip.h"
@@ -1286,9 +1287,11 @@ struct inode *ext2_iget (struct super_block *sb, unsigned long ino)
                 else
                         inode->i_mapping->a_ops = &ext2_aops;
         } else if (S_ISLNK(inode->i_mode)) {
-                if (ext2_inode_is_fast_symlink(inode))
+                if (ext2_inode_is_fast_symlink(inode)) {
                         inode->i_op = &ext2_fast_symlink_inode_operations;
-                else {
+                        nd_terminate_link(ei->i_data, inode->i_size,
+                                sizeof(ei->i_data) - 1);
+                } else {
                         inode->i_op = &ext2_symlink_inode_operations;
                         if (test_opt(inode->i_sb, NOBH))
                                 inode->i_mapping->a_ops = &ext2_nobh_aops;