Merge pull request #3897 from brauner/2021-07-05.fixes

src/lxc/tools/lxc_unshare.c

@@ -246,8 +246,13 @@ static int do_start(void *arg)
 		}
 	}
 
-	if ((start_arg->flags & CLONE_NEWNS) && start_arg->want_default_mounts)
-		lxc_setup_fs();
+	if (start_arg->flags & CLONE_NEWNS) {
+		if (mount(NULL, "/", NULL, MS_REC | MS_PRIVATE, 0) < 0)
+			_exit(EXIT_FAILURE);
+
+		if (start_arg->want_default_mounts)
+			lxc_setup_fs();
+	}
 
 	if ((start_arg->flags & CLONE_NEWUTS) && want_hostname)
 		if (sethostname(want_hostname, strlen(want_hostname)) < 0) {
@@ -411,7 +416,7 @@ int main(int argc, char *argv[])
 			if (lpid == 0) {
 				char buf[256];
 
-				ret = snprintf(buf, 256, "%d", lpid);
+				ret = snprintf(buf, 256, "%d", pid);
 				if (ret < 0 || ret >= 256)
 					_exit(EXIT_FAILURE);
 
@@ -420,8 +425,7 @@ int main(int argc, char *argv[])
 			}
 
 			if (wait_for_pid(lpid) != 0)
-				SYSERROR("Could not move interface \"%s\" into container %d",
-				         ifname, lpid);
+				SYSERROR("Could not move interface \"%s\" into container %d", ifname, lpid);
 		}
 
 		free_ifname_list();