Fix: Possible memory leak when multiple config files are loaded

Some configuration options could leak when initialized multiple times
from different configuration files and from the command line arguments.
The previous options are now freed' before being set.

Fixes #796

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

diff --git a/src/bin/lttng-sessiond/main.c b/src/bin/lttng-sessiond/main.c
index 6a918ec56a73926621a20119eb3e3686d0f3d998..cef1040563b1f84ae2af85235c80752aa4cabfe9 100644 (file)
--- a/src/bin/lttng-sessiond/main.c
+++ b/src/bin/lttng-sessiond/main.c
@@ -4198,11 +4198,20 @@ static int set_option(int opt, const char *arg, const char *optname)
                opt_background = 1;
                break;
        case 'g':
+               /*
+                * If the override option is set, the pointer points to a
+                * *non* const thus freeing it even though the variable type is
+                * set to const.
+                */
+               if (tracing_group_name_override) {
+                       free((void *) tracing_group_name);
+               }
                tracing_group_name = strdup(arg);
                if (!tracing_group_name) {
                        perror("strdup");
                        ret = -ENOMEM;
                }
+               tracing_group_name_override = 1;
                break;
        case 'h':
                usage();
@@ -4258,6 +4267,9 @@ static int set_option(int opt, const char *arg, const char *optname)
                }
                break;
        case 'u':
+               if (consumerd32_bin_override) {
+                       free((void *) consumerd32_bin);
+               }
                consumerd32_bin = strdup(arg);
                if (!consumerd32_bin) {
                        perror("strdup");
@@ -4266,6 +4278,9 @@ static int set_option(int opt, const char *arg, const char *optname)
                consumerd32_bin_override = 1;
                break;
        case 'U':
+               if (consumerd32_libdir_override) {
+                       free((void *) consumerd32_libdir);
+               }
                consumerd32_libdir = strdup(arg);
                if (!consumerd32_libdir) {
                        perror("strdup");
@@ -4274,6 +4289,9 @@ static int set_option(int opt, const char *arg, const char *optname)
                consumerd32_libdir_override = 1;
                break;
        case 't':
+               if (consumerd64_bin_override) {
+                       free((void *) consumerd64_bin);
+               }
                consumerd64_bin = strdup(arg);
                if (!consumerd64_bin) {
                        perror("strdup");
@@ -4282,6 +4300,9 @@ static int set_option(int opt, const char *arg, const char *optname)
                consumerd64_bin_override = 1;
                break;
        case 'T':
+               if (consumerd64_libdir_override) {
+                       free((void *) consumerd64_libdir);
+               }
                consumerd64_libdir = strdup(arg);
                if (!consumerd64_libdir) {
                        perror("strdup");
@@ -4290,6 +4311,7 @@ static int set_option(int opt, const char *arg, const char *optname)
                consumerd64_libdir_override = 1;
                break;
        case 'p':
+               free(opt_pidfile);
                opt_pidfile = strdup(arg);
                if (!opt_pidfile) {
                        perror("strdup");
@@ -4315,6 +4337,7 @@ static int set_option(int opt, const char *arg, const char *optname)
                break;
        }
        case 'l':
+               free(opt_load_session_path);
                opt_load_session_path = strdup(arg);
                if (!opt_load_session_path) {
                        perror("strdup");
@@ -4322,6 +4345,7 @@ static int set_option(int opt, const char *arg, const char *optname)
                }
                break;
        case 'P': /* probe modules list */
+               free(kmod_probes_list);
                kmod_probes_list = strdup(arg);
                if (!kmod_probes_list) {
                        perror("strdup");