gnutls: fix CVE-2021-4209

(From OE-Core rev: d08031bffafbd2df7e938d5599af9e818bddba04)

Signed-off-by: Chee Yang Lee <chee.yang.lee@intel.com>
Signed-off-by: Steve Sakoman <steve@sakoman.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-support/gnutls/gnutls/CVE-2021-4209.patch

@@ -0,0 +1,37 @@
+From 3db352734472d851318944db13be73da61300568 Mon Sep 17 00:00:00 2001
+From: Daiki Ueno <ueno@gnu.org>
+Date: Wed, 22 Dec 2021 09:12:25 +0100
+Subject: [PATCH] wrap_nettle_hash_fast: avoid calling _update with zero-length
+ input
+
+As Nettle's hash update functions internally call memcpy, providing
+zero-length input may cause undefined behavior.
+
+Signed-off-by: Daiki Ueno <ueno@gnu.org>
+
+https://gitlab.com/gnutls/gnutls/-/commit/3db352734472d851318944db13be73da61300568
+Upstream-Status: Backport
+CVE: CVE-2021-4209
+Signed-off-by: Chee Yang Lee <chee.yang.lee@intel.com>
+---
+ lib/nettle/mac.c | 4 +++-
+ 1 file changed, 3 insertions(+), 1 deletion(-)
+
+diff --git a/lib/nettle/mac.c b/lib/nettle/mac.c
+index f9d4d7a8df..35e070fab0 100644
+--- a/lib/nettle/mac.c
++++ b/lib/nettle/mac.c
+@@ -788,7 +788,9 @@ static int wrap_nettle_hash_fast(gnutls_digest_algorithm_t algo,
+ 	if (ret < 0)
+ 		return gnutls_assert_val(ret);
+ 
+-	ctx.update(&ctx, text_size, text);
++	if (text_size > 0) {
++		ctx.update(&ctx, text_size, text);
++	}
+ 	ctx.digest(&ctx, ctx.length, digest);
+ 
+ 	return 0;
+-- 
+GitLab
+

meta/recipes-support/gnutls/gnutls_3.6.14.bb

@@ -26,6 +26,7 @@ SRC_URI = "https://www.gnupg.org/ftp/gcrypt/gnutls/v${SHRT_VER}/gnutls-${PV}.tar
            file://CVE-2021-20231.patch \
            file://CVE-2021-20232.patch \
            file://CVE-2022-2509.patch \
+           file://CVE-2021-4209.patch \
 "
 
 SRC_URI[sha256sum] = "5630751adec7025b8ef955af4d141d00d252a985769f51b4059e5affa3d39d63"