From: Dr. Stephen Henson <steve@openssl.org>
Date: Fri, 19 Aug 2016 22:28:29 +0000 (+0100)
Subject: Avoid overflow in MDC2_Update()
X-Git-Tag: OpenSSL_1_0_2i~49
X-Git-Url: https://git.librecmc.org/?a=commitdiff_plain;h=1027ad4f34c30b8585592764b9a670ba36888269;p=oweals%2Fopenssl.git

Avoid overflow in MDC2_Update()

Thanks to Shi Lei for reporting this issue.

CVE-2016-6303

Reviewed-by: Matt Caswell <matt@openssl.org>
(cherry picked from commit 55d83bf7c10c7b205fffa23fa7c3977491e56c07)
---

diff --git a/crypto/mdc2/mdc2dgst.c b/crypto/mdc2/mdc2dgst.c
index 6615cf84d7..2dce493633 100644
--- a/crypto/mdc2/mdc2dgst.c
+++ b/crypto/mdc2/mdc2dgst.c
@@ -91,7 +91,7 @@ int MDC2_Update(MDC2_CTX *c, const unsigned char *in, size_t len)
 
     i = c->num;
     if (i != 0) {
-        if (i + len < MDC2_BLOCK) {
+        if (len < MDC2_BLOCK - i) {
             /* partial block */
             memcpy(&(c->data[i]), in, len);
             c->num += (int)len;