gnutls: patch read buffer overrun in the "pre_shared_key" extension

Pick relevant commit from 3.8.10 release MR [1].
The ME contains referece to undiscoled issue, so any security relevant
patch should be picked.

Binary test file was added as separate file as binary diffs are not
supported.

[1] https://gitlab.com/gnutls/gnutls/-/merge_requests/1979

(From OE-Core rev: 33181e3e8c7427fc823f750e936732b69e247987)

Signed-off-by: Peter Marko <peter.marko@siemens.com>
Signed-off-by: Steve Sakoman <steve@sakoman.com>

meta/recipes-support/gnutls/gnutls/0001-psk-fix-read-buffer-overrun-in-the-pre_shared_key-ex.patch

@@ -0,0 +1,34 @@
+From 208c6478d5c20b9d8a9f0a293e3808aa16ee091f Mon Sep 17 00:00:00 2001
+From: Andrew Hamilton <adhamilt@gmail.com>
+Date: Mon, 7 Jul 2025 10:31:55 +0900
+Subject: [PATCH] psk: fix read buffer overrun in the "pre_shared_key"
+ extension
+
+While processing the "pre_shared_key" extension in TLS 1.3, if there
+are certain malformed data in the extension headers, then the code may
+read uninitialized memory (2 bytes) beyond the received TLS extension
+buffer. Spotted by oss-fuzz at:
+https://issues.oss-fuzz.com/issues/42513990
+
+Signed-off-by: Andrew Hamilton <adhamilt@gmail.com>
+Signed-off-by: Daiki Ueno <ueno@gnu.org>
+
+Upstream-Status: Backport [https://gitlab.com/gnutls/gnutls/-/commit/208c6478d5c20b9d8a9f0a293e3808aa16ee091f]
+Signed-off-by: Peter Marko <peter.marko@siemens.com>
+---
+ lib/ext/pre_shared_key.c                          |   2 ++
+ 1 file changed, 2 insertions(+)
+
+diff --git a/lib/ext/pre_shared_key.c b/lib/ext/pre_shared_key.c
+index 51c4891d5..2cb83e670 100644
+--- a/lib/ext/pre_shared_key.c
++++ b/lib/ext/pre_shared_key.c
+@@ -839,6 +839,8 @@ static int _gnutls_psk_recv_params(gnutls_session_t session,
+ 
+ 	if (session->security_parameters.entity == GNUTLS_CLIENT) {
+ 		if (session->internals.hsk_flags & HSK_PSK_KE_MODES_SENT) {
++			DECR_LEN(len, 2);
++
+ 			uint16_t selected_identity = _gnutls_read_uint16(data);
+ 
+ 			for (i=0;i<sizeof(session->key.binders)/sizeof(session->key.binders[0]);i++) {

meta/recipes-support/gnutls/gnutls_3.7.4.bb

@@ -31,6 +31,8 @@ SRC_URI = "https://www.gnupg.org/ftp/gcrypt/gnutls/v${SHRT_VER}/gnutls-${PV}.tar
            file://CVE-2024-12243.patch \
            file://CVE-2025-32989.patch \
            file://04939b75417cc95b7372c6f208c4bda4579bdc34 \
+           file://0001-psk-fix-read-buffer-overrun-in-the-pre_shared_key-ex.patch \
+           file://5477db1bb507a35e8833c758ce344f4b5b246d8e \
            "
 
 SRC_URI[sha256sum] = "e6adbebcfbc95867de01060d93c789938cf89cc1d1f6ef9ef661890f6217451f"
@@ -69,8 +71,9 @@ do_configure:prepend() {
 	done
 
     # binary files cannot be delivered as diff
-    mkdir -p ${S}/fuzz/gnutls_x509_parser_fuzzer.repro/
+    mkdir -p ${S}/fuzz/gnutls_x509_parser_fuzzer.repro/ ${S}/fuzz/gnutls_psk_client_fuzzer.repro/
     cp ${WORKDIR}/04939b75417cc95b7372c6f208c4bda4579bdc34 ${S}/fuzz/gnutls_x509_parser_fuzzer.repro/
+    cp ${WORKDIR}/5477db1bb507a35e8833c758ce344f4b5b246d8e ${S}/fuzz/gnutls_psk_client_fuzzer.repro/
 }
 
 PACKAGES =+ "${PN}-openssl ${PN}-xx"