CVE-2026-0965 config: Do not attempt to read non-regular and too large configuration files

Changes also the reading of known_hosts to use the new helper function

Signed-off-by: Jakub Jelen <jjelen@redhat.com>
Reviewed-by: Andreas Schneider <asn@cryptomilk.org>
(cherry picked from commit a5eb30dbfd)

src/known_hosts.c

@@ -83,7 +83,7 @@ static struct ssh_tokens_st *ssh_get_knownhost_line(FILE **file,
     struct ssh_tokens_st *tokens = NULL;
 
     if (*file == NULL) {
-        *file = fopen(filename,"r");
+        *file = ssh_strict_fopen(filename, SSH_MAX_CONFIG_FILE_SIZE);
         if (*file == NULL) {
             return NULL;
         }