lxc-unshare: do not pass NULL pointer

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>

diff --git a/src/lxc/tools/lxc_unshare.c b/src/lxc/tools/lxc_unshare.c
index c294a6085d1fcfe79def72ef89f9981819f5ffb4..25af9711946eb4b20689d36d14a593c27f6fc58a 100644 (file)
--- a/src/lxc/tools/lxc_unshare.c
+++ b/src/lxc/tools/lxc_unshare.c
@@ -228,6 +228,9 @@ int main(int argc, char *argv[])
         *      dest: del + 1 == OUNT|PID
         *      src:  del + 3 == NT|PID
         */
+       if (!namespaces)
+               usage(argv[0]);
+
        while ((del = strstr(namespaces, "MOUNT")))
                memmove(del + 1, del + 3, strlen(del) - 2);