lxc: avoid memory corruption on ppc and s390 V4

conf object is on stack and is used in forked process.

Signed-off-by: Michel Normand <normand@fr.ibm.com>
Signed-off-by: Daniel Lezcano <dlezcano@fr.ibm.com>

4 files changed, 34 insertions, 22 deletions

diff --git a/src/lxc/conf.c b/src/lxc/conf.c
index da7c945..b56e880 100644
--- a/src/lxc/conf.c
+++ b/src/lxc/conf.c
@@ -815,18 +815,28 @@ out:
 	return ret;
 }
 
-int lxc_conf_init(struct lxc_conf *conf)
+struct lxc_conf *lxc_conf_init(void)
 {
-	conf->rootfs = NULL;
-	conf->fstab = NULL;
-	conf->utsname = NULL;
-	conf->tty = 0;
-	conf->pts = 0;
-	conf->console[0] = '\0';
-	lxc_list_init(&conf->cgroup);
-	lxc_list_init(&conf->network);
-	lxc_list_init(&conf->mount_list);
-	return 0;
+	struct lxc_conf *new;
+
+	new = 	malloc(sizeof(*new));
+	if (!new) {
+		ERROR("lxc_conf_init : %m");
+		return NULL;
+	}
+	memset(new, 0, sizeof(*new));
+
+	new->rootfs = NULL;
+	new->fstab = NULL;
+	new->utsname = NULL;
+	new->tty = 0;
+	new->pts = 0;
+	new->console[0] = '\0';
+	lxc_list_init(&new->cgroup);
+	lxc_list_init(&new->network);
+	lxc_list_init(&new->mount_list);
+
+	return new;
 }
 
 static int instanciate_veth(struct lxc_netdev *netdev)
diff --git a/src/lxc/conf.h b/src/lxc/conf.h
index 8548eeb..c4e5deb 100644
--- a/src/lxc/conf.h
+++ b/src/lxc/conf.h
@@ -171,7 +171,7 @@ struct lxc_conf {
 /*
  * Initialize the lxc configuration structure
  */
-extern int lxc_conf_init(struct lxc_conf *conf);
+extern struct lxc_conf *lxc_conf_init(void);
 
 extern int lxc_create_network(struct lxc_list *networks);
 extern int lxc_assign_network(struct lxc_list *networks, pid_t pid);
diff --git a/src/lxc/lxc_execute.c b/src/lxc/lxc_execute.c
index 40a4b93..50fec10 100644
--- a/src/lxc/lxc_execute.c
+++ b/src/lxc/lxc_execute.c
@@ -84,7 +84,7 @@ int main(int argc, char *argv[])
 {
 	static char **args;
 	char *rcfile;
-	struct lxc_conf conf;
+	struct lxc_conf *conf;
 
 	if (lxc_arguments_parse(&my_args, argc, argv))
 		return -1;
@@ -113,16 +113,17 @@ int main(int argc, char *argv[])
 		}
 	}
 
-	if (lxc_conf_init(&conf)) {
-		ERROR("failed to initialze configuration");
+	conf = lxc_conf_init();
+	if (!conf) {
+		ERROR("failed to initialize configuration");
 		return -1;
 	}
 
-	if (rcfile && lxc_config_read(rcfile, &conf)) {
+	if (rcfile && lxc_config_read(rcfile, conf)) {
 		ERROR("failed to read configuration file");
 		return -1;
 	}
 
-	return lxc_start(my_args.name, args, &conf);
+	return lxc_start(my_args.name, args, conf);
 }
 
diff --git a/src/lxc/lxc_start.c b/src/lxc/lxc_start.c
index d2471eb..fdd3b15 100644
--- a/src/lxc/lxc_start.c
+++ b/src/lxc/lxc_start.c
@@ -133,7 +133,7 @@ int main(int argc, char *argv[])
 	};
 
 	char *rcfile = NULL;
-	struct lxc_conf conf;
+	struct lxc_conf *conf;
 
 	if (lxc_arguments_parse(&my_args, argc, argv))
 		return err;
@@ -163,12 +163,13 @@ int main(int argc, char *argv[])
 		}
 	}
 
-	if (lxc_conf_init(&conf)) {
-		ERROR("failed to initialze configuration");
+	conf = lxc_conf_init();
+	if (!conf) {
+		ERROR("failed to initialize configuration");
 		return err;
 	}
 
-	if (rcfile && lxc_config_read(rcfile, &conf)) {
+	if (rcfile && lxc_config_read(rcfile, conf)) {
 		ERROR("failed to read configuration file");
 		return err;
 	}
@@ -204,7 +205,7 @@ int main(int argc, char *argv[])
 
 	save_tty(&tios);
 
-	err = lxc_start(my_args.name, args, &conf);
+	err = lxc_start(my_args.name, args, conf);
 
 	restore_tty(&tios);