Squashfs: sanity check information from disk

We read the size of the name from the disk, but a larger name than
expected would cause memory corruption.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>

1 files changed, 6 insertions, 1 deletions

diff --git a/fs/squashfs/namei.c b/fs/squashfs/namei.c
index 7834a517f7f4..f866d42a8b6f 100644
--- a/fs/squashfs/namei.c
+++ b/fs/squashfs/namei.c
@@ -79,7 +79,8 @@ static int get_dir_index_using_name(struct super_block *sb,
                         int len)
 {
         struct squashfs_sb_info *msblk = sb->s_fs_info;
-        int i, size, length = 0, err;
+        int i, length = 0, err;
+        unsigned int size;
         struct squashfs_dir_index *index;
         char *str;
 
@@ -103,6 +104,10 @@ static int get_dir_index_using_name(struct super_block *sb,
 
 
                 size = le32_to_cpu(index->size) + 1;
+                if (size > SQUASHFS_NAME_LEN) {
+                        err = -EINVAL;
+                        break;
+                }
 
                 err = squashfs_read_metadata(sb, index->name, &index_start,
                                         &index_offset, size);