From: Matt Caswell <matt@openssl.org>
Date: Tue, 25 Apr 2023 10:39:26 +0000 (+0100)
Subject: Release zero length handshake fragment records
X-Git-Tag: openssl-3.2.0-alpha1~939
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c20d923b46641030cb2946a1922ee344b9d27e43;p=thirdparty%2Fopenssl.git

Release zero length handshake fragment records

If we are processing a hanshake fragment and we end up with a
zero length record, then we still need to release it to avoid an
infinite loop.

Fixes #20821

Reviewed-by: Todd Short <todd.short@me.com>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/20824)
---

diff --git a/ssl/record/rec_layer_s3.c b/ssl/record/rec_layer_s3.c
index bba8b7fa026..f9806e97991 100644
--- a/ssl/record/rec_layer_s3.c
+++ b/ssl/record/rec_layer_s3.c
@@ -939,9 +939,13 @@ int ssl3_read_bytes(SSL *ssl, int type, int *recvd_type, unsigned char *buf,
         if (n > 0) {
             memcpy(dest + *dest_len, rr->data + rr->off, n);
             *dest_len += n;
-            if (!ssl_release_record(s, rr, n))
-                return -1;
         }
+        /*
+         * We release the number of bytes consumed, or the whole record if it
+         * is zero length
+         */
+        if ((n > 0 || rr->length == 0) && !ssl_release_record(s, rr, n))
+            return -1;
 
         if (*dest_len < dest_maxlen)
             goto start;     /* fragment was too small */