From 3e9175e66ac58c6ff2c1152fab6cbfb5337e4189 Mon Sep 17 00:00:00 2001
From: Jakub Jelen <jjelen@redhat.com>
Date: Mon, 24 Nov 2025 17:51:06 +0100
Subject: [PATCH] server: Check strdup allocation failure
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Thanks Xiaoke Wang for the report!

Signed-off-by: Jakub Jelen <jjelen@redhat.com>
Reviewed-by: Pavol Žáčik <pzacik@redhat.com>
Reviewed-by: Andreas Schneider <asn@cryptomilk.org>
(cherry picked from commit ee180c660e7b53f84c1c46b3efd20a7a5d6a1dd7)
---
 src/server.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/server.c b/src/server.c
index c6ad11f9..961c25a0 100644
--- a/src/server.c
+++ b/src/server.c
@@ -495,6 +495,11 @@ static size_t callback_receive_banner(const void *data, size_t len, void *user)
             buffer[i] = '\0';
 
             str = strdup(buffer);
+            if (str == NULL) {
+                session->session_state = SSH_SESSION_STATE_ERROR;
+                ssh_set_error_oom(session);
+                return 0;
+            }
             /* number of bytes read */
             processed = i + 1;
             session->clientbanner = str;