The patch titled
Subject: selftests/exec: test for empty string on NULL argv
has been added to the -mm tree. Its filename is
selftests-exec-test-for-empty-string-on-null-argv.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/selftests-exec-test-for-empty-string-on-null-argv.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/selftests-exec-test-for-empty-string-on-null-argv.patch
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*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next and is updated
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------------------------------------------------------
From: Kees Cook <keescook@xxxxxxxxxxxx>
Subject: selftests/exec: test for empty string on NULL argv
Test for the NULL argv argument producing a single empty string on exec.
Link: https://lkml.kernel.org/r/20220201011637.2457646-1-keescook@xxxxxxxxxxxx
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: Eric Biederman <ebiederm@xxxxxxxxxxxx>
Cc: Shuah Khan <shuah@xxxxxxxxxx>
Cc: Yang Yingliang <yangyingliang@xxxxxxxxxx>
Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Ariadne Conill <ariadne@xxxxxxxxxxxxxxxx>
Cc: Christian Brauner <brauner@xxxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Michael Kerrisk <mtk.manpages@xxxxxxxxx>
Cc: Rich Felker <dalias@xxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
tools/testing/selftests/exec/Makefile | 1
tools/testing/selftests/exec/null-argv.c | 78 +++++++++++++++++++++
2 files changed, 79 insertions(+)
--- a/tools/testing/selftests/exec/Makefile~selftests-exec-test-for-empty-string-on-null-argv
+++ a/tools/testing/selftests/exec/Makefile
@@ -10,6 +10,7 @@ TEST_GEN_FILES := execveat.symlink execv
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
--- /dev/null
+++ a/tools/testing/selftests/exec/null-argv.c
@@ -0,0 +1,78 @@
+// 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);
+}
_
Patches currently in -mm which might be from keescook@xxxxxxxxxxxx are
kconfigdebug-make-debug_info-selectable-from-a-choice.patch
kconfigdebug-make-debug_info-selectable-from-a-choice-fix.patch
exec-force-single-empty-string-when-argv-is-empty.patch
selftests-exec-test-for-empty-string-on-null-argv.patch
