From: Valentine Krasnobaeva <vkrasnobaeva@haproxy.com>
Date: Thu, 8 Aug 2024 14:34:54 +0000 (+0200)
Subject: MINOR: cfgparse: load_cfg_in_mem: fix null ptr dereference reported by coverity
X-Git-Tag: v3.1-dev6~61
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=da82f08055a74f2736b779893f9c970b5e862695;p=thirdparty%2Fhaproxy.git

MINOR: cfgparse: load_cfg_in_mem: fix null ptr dereference reported by coverity

This helps to optimize a bit load_cfg_in_mem() and fixes the potential null ptr
dereference in fread() call. If (read_bytes + bytes_to_read) equals to initial
chunk_size (zero), realloc is never called, *cfg_content keeps its NULL value.

So, let's assure that initial number of bytes to read
(read_bytes + bytes_to_read) is stricly positive, when we enter into loop at
the first time.
---

diff --git a/src/cfgparse.c b/src/cfgparse.c
index 24c22f9cc4..bf43b02fd1 100644
--- a/src/cfgparse.c
+++ b/src/cfgparse.c
@@ -1771,10 +1771,9 @@ ssize_t load_cfg_in_mem(char *filename, char **cfg_content)
 		return -1;
 	}
 
-	if (file_stat.st_size) {
-		/* as we need to read EOF to have feof(f)=1 */
-		bytes_to_read = file_stat.st_size + 1;
-	}
+	if (file_stat.st_size > chunk_size)
+		bytes_to_read = file_stat.st_size;
+
 
 	if ((f = fopen(filename,"r")) == NULL) {
 		ha_alert("Could not open configuration file %s : %s\n",