openssl fix for CVE-2010-5298

Upstream-Status: Backport

Race condition in the ssl3_read_bytes function in s3_pkt.c in OpenSSL
through 1.0.1g, when SSL_MODE_RELEASE_BUFFERS is enabled, allows remote
attackers to inject data across sessions or cause a denial of service
(use-after-free and parsing error) via an SSL connection in a
multithreaded environment.

http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2010-5298

Signed-off-by: Yue Tao <Yue.Tao@windriver.com>
--- a/ssl/s3_pkt.c
+++ b/ssl/s3_pkt.c
@@ -1013,7 +1013,7 @@ start:
 				{
 				s->rstate=SSL_ST_READ_HEADER;
 				rr->off=0;
-				if (s->mode & SSL_MODE_RELEASE_BUFFERS)
+				if (s->mode & SSL_MODE_RELEASE_BUFFERS && s->s3->rbuf.left == 0)
 					ssl3_release_read_buffer(s);
 				}
 			}