openssh: fix CVE-2026-73283

This patch applies the upstream fix that makes the authorized_keys
restrict keyword apply to tunnel forwarding. The upstream fix commit
is referenced in [1], and the public CVE advisory is referenced in [2].

[1] https://github.com/openssh/openssh-portable/commit/d322f2ccf7da095ce94d1d99cb563246f61487b
[2] https://www.cve.org/CVERecord?id=CVE-2026-73283

(From OE-Core rev: 9eafc35227e70fc4a0979e99b77a804684ef9bf1)

Signed-off-by: Hetvi Thakar <hthakar@cisco.com>
Signed-off-by: Yoann Congal <yoann.congal@smile.fr>
Signed-off-by: Paul Barker <paul@pbarker.dev>

meta/recipes-connectivity/openssh/openssh/CVE-2026-73283.patch

@@ -0,0 +1,42 @@
+From d322f2ccf7da095ce94d1d99cb563246f61487b0 Mon Sep 17 00:00:00 2001
+From: djm@openbsd.org <djm@openbsd.org>
+Date: Tue, 14 Jul 2026 01:05:05 +0000
+Subject: [PATCH] upstream: make authorized_keys "restrict" keyword apply
+ correctly
+
+to tunnel forwarding (which is administratively disabled by default).
+
+Reported by Erichen, Institute of Computing Technology,
+Chinese Academy of Sciences
+
+OpenBSD-Commit-ID: 5b3cc987a64749c94b20e12755db32a83f8f01e6
+
+CVE: CVE-2026-73283
+Upstream-Status: Backport [https://github.com/openssh/openssh-portable/commit/d322f2ccf7da095ce94d1d99cb563246f61487b0]
+
+Backport Changes:
+- Omitted the upstream OpenBSD RCS revision header update because it does
+  not apply to the OpenSSH 9.6p1 source revision.
+
+(cherry picked from commit d322f2ccf7da095ce94d1d99cb563246f61487b0)
+Signed-off-by: Hetvi Thakar <hthakar@cisco.com>
+---
+ serverloop.c | 3 ++-
+ 1 file changed, 2 insertions(+), 1 deletion(-)
+
+diff --git a/serverloop.c b/serverloop.c
+index c1fe99d1..56d8be75 100644
+--- a/serverloop.c
++++ b/serverloop.c
+@@ -531,7 +531,8 @@ server_request_tun(struct ssh *ssh)
+ 		ssh_packet_send_debug(ssh, "Unsupported tunnel device mode.");
+ 		return NULL;
+ 	}
+-	if ((options.permit_tun & mode) == 0 || options.disable_forwarding) {
++	if ((options.permit_tun & mode) == 0 || options.disable_forwarding ||
++	    auth_opts->restricted) {
+ 		ssh_packet_send_debug(ssh, "Server has rejected tunnel device "
+ 		    "forwarding");
+ 		return NULL;
+-- 
+2.43.0

meta/recipes-connectivity/openssh/openssh_9.6p1.bb

@@ -44,6 +44,7 @@ SRC_URI = "http://ftp.openbsd.org/pub/OpenBSD/OpenSSH/portable/openssh-${PV}.tar
            file://CVE-2026-60001.patch \
            file://CVE-2026-60002.patch \
            file://CVE-2026-60000.patch \
+           file://CVE-2026-73283.patch \
            "
 SRC_URI[sha256sum] = "910211c07255a8c5ad654391b40ee59800710dd8119dd5362de09385aa7a777c"