From bbe75a29dfdb6561f21b7d010ac18c52da4beb78 Mon Sep 17 00:00:00 2001
From: Matt Caswell <matt@openssl.org>
Date: Wed, 16 May 2018 11:59:47 +0100
Subject: [PATCH] Fix undefined behaviour in X509_NAME_cmp()
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 | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/crypto/x509/x509_cmp.c b/crypto/x509/x509_cmp.c
index 01056356c5..8ac9efea42 100644
--- a/crypto/x509/x509_cmp.c
+++ b/crypto/x509/x509_cmp.c
@@ -174,7 +174,7 @@ 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);
--
2.25.1