From eb9dc8cfc45875ddf8dd193eb16e506937ce5355 Mon Sep 17 00:00:00 2001
From: Norbert Pocs <[email protected]>
Date: Tue, 7 Jun 2022 14:28:30 +0200
Subject: [PATCH] Add errno reset with strtoul call

Contaminated errno can happen before strtoul call, thereofore
cleaning it before the call.
The errno is not used for checking later in code if fail happens,
therefore cleaning it right after error.

Signed-off-by: Norbert Pocs <[email protected]>
Reviewed-by: Jakub Jelen <[email protected]>
---
 src/misc.c           | 4 ++++
 tests/pkd/pkd_util.c | 1 +
 2 files changed, 5 insertions(+)

diff --git a/src/misc.c b/src/misc.c
index f7efb9df..e890e829 100644
--- a/src/misc.c
+++ b/src/misc.c
@@ -1361,21 +1361,25 @@ int ssh_analyze_banner(ssh_session session, int server)
          * 012345678901234567890
          */
         if (strlen(openssh) > 9) {
+            errno = 0;
             major = strtoul(openssh + 8, &tmp, 10);
             if ((tmp == (openssh + 8)) ||
                 ((errno == ERANGE) && (major == ULONG_MAX)) ||
                 ((errno != 0) && (major == 0)) ||
                 ((major < 1) || (major > 100))) {
                 /* invalid major */
+                errno = 0;
                 goto done;
             }
 
+            errno = 0;
             minor = strtoul(openssh + 10, &tmp, 10);
             if ((tmp == (openssh + 10)) ||
                 ((errno == ERANGE) && (major == ULONG_MAX)) ||
                 ((errno != 0) && (major == 0)) ||
                 (minor > 100)) {
                 /* invalid minor */
+                errno = 0;
                 goto done;
             }
 
diff --git a/tests/pkd/pkd_util.c b/tests/pkd/pkd_util.c
index 0e3b19b4..e8e6fbb7 100644
--- a/tests/pkd/pkd_util.c
+++ b/tests/pkd/pkd_util.c
@@ -81,6 +81,7 @@ static int is_openssh_client_new_enough(void) {
         ((major < 1) || (major > 100))) {
         fprintf(stderr, "failed to parse OpenSSH client version, "
                         "errno %d\n", errno);
+        errno = 0;
         goto errversion;
     }
 
-- 
2.33.0