Commit 9132c394 authored by Kees Cook's avatar Kees Cook
Browse files

selftests/exec: Test for empty string on NULL argv 



Test for the NULL argv argument producing a single empty string on exec.

Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Yang Yingliang <yangyingliang@huawei.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-kselftest@vger.kernel.org
Signed-off-by: default avatarKees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/lkml/20220201011637.2457646-1-keescook@chromium.org
parent dcd46d89

tools/testing/selftests/exec/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -10,6 +10,7 @@ TEST_GEN_FILES := execveat.symlink execveat.denatured script subdir 
TEST_FILES := Makefile



TEST_GEN_PROGS += recursion-depth

TEST_GEN_PROGS += null-argv



EXTRA_CLEAN := $(OUTPUT)/subdir.moved $(OUTPUT)/execveat.moved $(OUTPUT)/xxxxx*	\

	       $(OUTPUT)/S_I*.test

tools/testing/selftests/exec/null-argv.c

0 → 100644
+78 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0-only

/* Test that empty argvs are swapped out for a single empty string. */

#include <stdio.h>

#include <unistd.h>

#include <sys/types.h>

#include <sys/wait.h>



#include "../kselftest.h"



#define FORK(exec)				\

do {						\

	pid = fork();				\

	if (pid == 0) {				\

		/* Child */			\

		exec; /* Some kind of exec */	\

		perror("# " #exec);		\

		return 1;			\

	}					\

	check_result(pid, #exec);		\

} while (0)



void check_result(pid_t pid, const char *msg)

{

	int wstatus;



	if (pid == (pid_t)-1) {

		perror("# fork");

		ksft_test_result_fail("fork failed: %s\n", msg);

		return;

	}

	if (waitpid(pid, &wstatus, 0) < 0) {

		perror("# waitpid");

		ksft_test_result_fail("waitpid failed: %s\n", msg);

		return;

	}

	if (!WIFEXITED(wstatus)) {

		ksft_test_result_fail("child did not exit: %s\n", msg);

		return;

	}

	if (WEXITSTATUS(wstatus) != 0) {

		ksft_test_result_fail("non-zero exit: %s\n", msg);

		return;

	}

	ksft_test_result_pass("%s\n", msg);

}



int main(int argc, char *argv[], char *envp[])

{

	pid_t pid;

	static char * const args[] = { NULL };

	static char * const str[] = { "", NULL };



	/* argc counting checks */

	if (argc < 1) {

		fprintf(stderr, "# FAIL: saw argc == 0 (old kernel?)\n");

		return 1;

	}

	if (argc != 1) {

		fprintf(stderr, "# FAIL: unknown argc (%d)\n", argc);

		return 1;

	}

	if (argv[0][0] == '\0') {

		/* Good, we found a NULL terminated string at argv[0]! */

		return 0;

	}



	/* Test runner. */

	ksft_print_header();

	ksft_set_plan(5);



	FORK(execve(argv[0], str, NULL));

	FORK(execve(argv[0], NULL, NULL));

	FORK(execve(argv[0], NULL, envp));

	FORK(execve(argv[0], args, NULL));

	FORK(execve(argv[0], args, envp));



	ksft_exit(ksft_cnt.ksft_pass == ksft_plan);

}