52 lines
1.1 KiB
C
52 lines
1.1 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
|
|
/*
|
|
* Copyright (c) 2022 Cyril Hrubis <chrubis@suse.cz>
|
|
*/
|
|
|
|
/*\
|
|
* [Description]
|
|
*
|
|
* Test that kernel adds dummy argv[0] if empty argument list was passed to
|
|
* execve(). This fixes at least one CVE where userspace programs start to
|
|
* process argument list blindly from argv[1] such as polkit pkexec
|
|
* CVE-2021-4034.
|
|
*
|
|
* See also https://lwn.net/Articles/883547/
|
|
*/
|
|
|
|
#include <stdlib.h>
|
|
#include <stdio.h>
|
|
#include "tst_test.h"
|
|
|
|
static void verify_execve(void)
|
|
{
|
|
pid_t pid;
|
|
char path[512];
|
|
char ipc_env_var[1024];
|
|
|
|
sprintf(ipc_env_var, IPC_ENV_VAR "=%s", getenv(IPC_ENV_VAR));
|
|
|
|
char *const envp[] = {ipc_env_var, NULL};
|
|
char *const argv[] = {NULL};
|
|
|
|
if (tst_get_path("execve06_child", path, sizeof(path)))
|
|
tst_brk(TCONF, "Couldn't find execve06_child in $PATH");
|
|
|
|
pid = SAFE_FORK();
|
|
if (pid == 0) {
|
|
execve(path, argv, envp);
|
|
tst_brk(TFAIL | TERRNO, "Failed to execute execl01_child");
|
|
}
|
|
}
|
|
|
|
static struct tst_test test = {
|
|
.forks_child = 1,
|
|
.child_needs_reinit = 1,
|
|
.test_all = verify_execve,
|
|
.tags = (const struct tst_tag[]) {
|
|
{"linux-git", "dcd46d897adb"},
|
|
{"CVE", "2021-4034"},
|
|
{}
|
|
}
|
|
};
|