From: Daniel Gustafsson <daniel@yesql.se>
Date: Thu, 12 May 2022 12:11:52 +0000 (+0200)
Subject: gssapi: improve handling of errors from gss_display_status
X-Git-Tag: curl-7_84_0~205
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=7360f9a5656b04d062cd86bfc1d045e526798d33;p=thirdparty%2Fcurl.git

gssapi: improve handling of errors from gss_display_status

In case gss_display_status() returns an error, avoid trying to add
it to the buffer as the message may well be a NULL pointer.

Originally this fix comes from a discussion in issue #8816.

Closes: #8832
Reviewed-by: Jay Satiro <raysatiro@yahoo.com>
---

diff --git a/lib/curl_gssapi.c b/lib/curl_gssapi.c
index 1543a0ff46..52510f4433 100644
--- a/lib/curl_gssapi.c
+++ b/lib/curl_gssapi.c
@@ -98,10 +98,12 @@ static size_t display_gss_error(OM_uint32 status, int type,
                                   GSS_C_NO_OID,
                                   &msg_ctx,
                                   &status_string);
-    if(GSS_LOG_BUFFER_LEN > len + status_string.length + 3) {
-      len += msnprintf(buf + len, GSS_LOG_BUFFER_LEN - len,
-                       "%.*s. ", (int)status_string.length,
-                       (char *)status_string.value);
+    if(maj_stat == GSS_S_COMPLETE && status_string.length > 0) {
+      if(GSS_LOG_BUFFER_LEN > len + status_string.length + 3) {
+        len += msnprintf(buf + len, GSS_LOG_BUFFER_LEN - len,
+                         "%.*s. ", (int)status_string.length,
+                         (char *)status_string.value);
+      }
     }
     gss_release_buffer(&min_stat, &status_string);
   } while(!GSS_ERROR(maj_stat) && msg_ctx);