cifs: Skip any trailing backslashes from UNC

When extracting hostname from UNC, check for leading backslashes
before trying to remove them.

Signed-off-by: Paulo Alcantara <palcantara@suse.de>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 944188d6200c246da16e68364bae713737a9c6a2..bab4422f58157fab2debcb176c5acbbc3cc7d7a5 100644 (file)
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -1044,7 +1044,12 @@ extract_hostname(const char *unc)
 
        /* skip double chars at beginning of string */
        /* BB: check validity of these bytes? */
-       src = unc + 2;
+       if (strlen(unc) < 3)
+               return ERR_PTR(-EINVAL);
+       for (src = unc; *src && *src == '\\'; src++)
+               ;
+       if (!*src)
+               return ERR_PTR(-EINVAL);
 
        /* delimiter between hostname and sharename is always '\\' now */
        delim = strchr(src, '\\');