Fix crash in dtls1_get_record whilst in the listen state where you ge…

…t two separate reads performed - one for the header and one for the body of the handshake record. CVE-2014-3571 Reviewed-by: Matt Caswell <matt@openssl.org>
openssl · Jan 8, 2015 · 8d7aab9 · 8d7aab9
1 parent e078642
commit 8d7aab9
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Showing 2 changed files with 2 additions and 2 deletions.
diff --git a/ssl/d1_pkt.c b/ssl/d1_pkt.c
@@ -642,8 +642,6 @@ int dtls1_get_record(SSL *s)
 		/* now s->packet_length == DTLS1_RT_HEADER_LENGTH */
 		i=rr->length;
 		n=ssl3_read_n(s,i,i,1);
-		if (n <= 0) return(n); /* error or non-blocking io */
-
 		/* this packet contained a partial record, dump it */
 		if ( n != i)
 			{

diff --git a/ssl/s3_pkt.c b/ssl/s3_pkt.c
@@ -183,6 +183,8 @@ int ssl3_read_n(SSL *s, int n, int max, int extend)
 	 * at once (as long as it fits into the buffer). */
 	if (SSL_version(s) == DTLS1_VERSION || SSL_version(s) == DTLS1_BAD_VER)
 		{
+		if (left == 0 && extend)
+			return 0;
 		if (left > 0 && n > left)
 			n = left;
 		}