Fix undefined behaviour in X509_NAME_cmp()
authorMatt Caswell <matt@openssl.org>
Wed, 16 May 2018 10:59:47 +0000 (11:59 +0100)
committerMatt Caswell <matt@openssl.org>
Mon, 21 May 2018 09:31:07 +0000 (10:31 +0100)
If the lengths of both names is 0 then don't attempt to do a memcmp.

Issue reported by Simon Friedberger, Robert Merget and Juraj Somorovsky.

Reviewed-by: Matthias St. Pierre <Matthias.St.Pierre@ncp-e.com>
(Merged from https://github.com/openssl/openssl/pull/6291)

(cherry picked from commit 511190b691183a1fb160e7e05e2974dc73cab0c6)

crypto/x509/x509_cmp.c

index 49c71b9..2d82f8f 100644 (file)
@@ -219,7 +219,7 @@ int X509_NAME_cmp(const X509_NAME *a, const X509_NAME *b)
 
     ret = a->canon_enclen - b->canon_enclen;
 
-    if (ret)
+    if (ret != 0 || a->canon_enclen == 0)
         return ret;
 
     return memcmp(a->canon_enc, b->canon_enc, a->canon_enclen);