From 6adc75887dddba9d694d14f40e16421d7f8b7fb7 Mon Sep 17 00:00:00 2001
From: RainRat <rainrat78@yahoo.ca>
Date: Thu, 30 Nov 2023 16:15:03 -0800
Subject: [PATCH] Fix possible memory leak if memory reallocation fails

In clamav-milter's `allow_list.c` `cli_regex2suffix`, if the realloc
fails it's possible the original memory may not be free'd.

Fixes: https://github.com/Cisco-Talos/clamav/issues/1092
---
 clamav-milter/allow_list.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/clamav-milter/allow_list.c b/clamav-milter/allow_list.c
index 09f37ff560..50f9ed2bd0 100644
--- a/clamav-milter/allow_list.c
+++ b/clamav-milter/allow_list.c
@@ -156,13 +156,15 @@ int smtpauth_init(const char *r)
             }
             if (len <= 0) continue;
             if (len * 3 + 1 > rxavail) {
-                ptr   = regex;
-                regex = realloc(regex, rxsize + 2048);
-                if (!regex) {
+                ptr        = regex;
+                char *temp = realloc(regex, rxsize + 2048);
+                if (!temp) {
+                    free(regex);
                     logg(LOGG_ERROR, "Cannot allocate memory for SkipAuthenticated file\n");
                     fclose(f);
                     return 1;
                 }
+                regex   = temp;
                 rxavail = 2048;
                 rxsize += 2048;
                 if (!ptr) {