From: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Date: Thu, 30 Nov 2017 23:18:03 +0000 (+0100)
Subject: Fix: using putenv() and free()-ing the value is invalid
X-Git-Url: http://git.efficios.com/?p=lttng-tools.git;a=commitdiff_plain;h=d222983eed2efddbd4a1380e23bc3f43edfc522e

Fix: using putenv() and free()-ing the value is invalid

putenv() does not copy the string passed as the parameter. Hence,
free()-ing the string results in an invalid environment. In the
"good" case, we don't care since we execl().

However, on error, our process now has an invalid environment
which can cause breakage further down the line.

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
---

diff --git a/src/bin/lttng-sessiond/main.c b/src/bin/lttng-sessiond/main.c
index 968fec84a..297db20ce 100644
--- a/src/bin/lttng-sessiond/main.c
+++ b/src/bin/lttng-sessiond/main.c
@@ -2450,20 +2450,18 @@ static pid_t spawn_consumerd(struct consumer_data *consumer_data)
 				if (!tmp) {
 					tmp = "";
 				}
-				tmplen = strlen("LD_LIBRARY_PATH=")
-					+ strlen(config.consumerd64_lib_dir.value) + 1 /* : */ + strlen(tmp);
+				tmplen = strlen(config.consumerd64_lib_dir.value) + 1 /* : */ + strlen(tmp);
 				tmpnew = zmalloc(tmplen + 1 /* \0 */);
 				if (!tmpnew) {
 					ret = -ENOMEM;
 					goto error;
 				}
-				strcpy(tmpnew, "LD_LIBRARY_PATH=");
 				strcat(tmpnew, config.consumerd64_lib_dir.value);
 				if (tmp[0] != '\0') {
 					strcat(tmpnew, ":");
 					strcat(tmpnew, tmp);
 				}
-				ret = putenv(tmpnew);
+				ret = setenv("LD_LIBRARY_PATH", tmpnew, 1);
 				if (ret) {
 					ret = -errno;
 					free(tmpnew);
@@ -2491,20 +2489,18 @@ static pid_t spawn_consumerd(struct consumer_data *consumer_data)
 				if (!tmp) {
 					tmp = "";
 				}
-				tmplen = strlen("LD_LIBRARY_PATH=")
-					+ strlen(config.consumerd32_lib_dir.value) + 1 /* : */ + strlen(tmp);
+				tmplen = strlen(config.consumerd32_lib_dir.value) + 1 /* : */ + strlen(tmp);
 				tmpnew = zmalloc(tmplen + 1 /* \0 */);
 				if (!tmpnew) {
 					ret = -ENOMEM;
 					goto error;
 				}
-				strcpy(tmpnew, "LD_LIBRARY_PATH=");
 				strcat(tmpnew, config.consumerd32_lib_dir.value);
 				if (tmp[0] != '\0') {
 					strcat(tmpnew, ":");
 					strcat(tmpnew, tmp);
 				}
-				ret = putenv(tmpnew);
+				ret = setenv("LD_LIBRARY_PATH", tmpnew, 1);
 				if (ret) {
 					ret = -errno;
 					free(tmpnew);