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 6113f49ade90cea6e02e7a4c74c296fa82acdbc1..ea28feecfd0888d644edce7bf4ff70fbe36c0730 100644 (file)
--- 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);