The patch titled
Subject: kselftest: vm: add tests for memory-deny-write-execute
has been added to the -mm mm-unstable branch. Its filename is
kselftest-vm-add-tests-for-memory-deny-write-execute.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/kselftest-vm-add-tests-for-memory-deny-write-execute.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days
------------------------------------------------------
From: Kees Cook <keescook@xxxxxxxxxxxx>
Subject: kselftest: vm: add tests for memory-deny-write-execute
Date: Thu, 19 Jan 2023 16:03:44 +0000
Add some tests to cover the new PR_SET_MDWE prctl.
Link: https://lkml.kernel.org/r/20230119160344.54358-3-joey.gouly@xxxxxxx
Co-developed-by: Joey Gouly <joey.gouly@xxxxxxx>
Signed-off-by: Joey Gouly <joey.gouly@xxxxxxx>
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: Shuah Khan <shuah@xxxxxxxxxx>
Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Jeremy Linton <jeremy.linton@xxxxxxx>
Cc: Lennart Poettering <lennart@xxxxxxxxxxxxxx>
Cc: Mark Brown <broonie@xxxxxxxxxx>
Cc: nd <nd@xxxxxxx>
Cc: Szabolcs Nagy <szabolcs.nagy@xxxxxxx>
Cc: Topi Miettinen <toiwoton@xxxxxxxxx>
Cc: Zbigniew JÄ?drzejewski-Szmek <zbyszek@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
--- a/tools/testing/selftests/mm/Makefile~kselftest-vm-add-tests-for-memory-deny-write-execute
+++ a/tools/testing/selftests/mm/Makefile
@@ -60,6 +60,7 @@ TEST_GEN_PROGS += soft-dirty
TEST_GEN_PROGS += split_huge_page_test
TEST_GEN_FILES += ksm_tests
TEST_GEN_PROGS += ksm_functional_tests
+TEST_GEN_PROGS += mdwe_test
ifeq ($(MACHINE),x86_64)
CAN_BUILD_I386 := $(shell ./../x86/check_cc.sh "$(CC)" ../x86/trivial_32bit_program.c -m32)
--- /dev/null
+++ a/tools/testing/selftests/mm/mdwe_test.c
@@ -0,0 +1,197 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#ifdef __aarch64__
+#include <asm/hwcap.h>
+#endif
+
+#include <linux/mman.h>
+#include <linux/prctl.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/auxv.h>
+#include <sys/prctl.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+#include "../kselftest_harness.h"
+
+#ifndef __aarch64__
+# define PROT_BTI 0
+#endif
+
+TEST(prctl_flags)
+{
+ EXPECT_LT(prctl(PR_SET_MDWE, 7L, 0L, 0L, 0L), 0);
+ EXPECT_LT(prctl(PR_SET_MDWE, 0L, 7L, 0L, 0L), 0);
+ EXPECT_LT(prctl(PR_SET_MDWE, 0L, 0L, 7L, 0L), 0);
+ EXPECT_LT(prctl(PR_SET_MDWE, 0L, 0L, 0L, 7L), 0);
+
+ EXPECT_LT(prctl(PR_GET_MDWE, 7L, 0L, 0L, 0L), 0);
+ EXPECT_LT(prctl(PR_GET_MDWE, 0L, 7L, 0L, 0L), 0);
+ EXPECT_LT(prctl(PR_GET_MDWE, 0L, 0L, 7L, 0L), 0);
+ EXPECT_LT(prctl(PR_GET_MDWE, 0L, 0L, 0L, 7L), 0);
+}
+
+FIXTURE(mdwe)
+{
+ void *p;
+ int flags;
+ size_t size;
+ pid_t pid;
+};
+
+FIXTURE_VARIANT(mdwe)
+{
+ bool enabled;
+ bool forked;
+};
+
+FIXTURE_VARIANT_ADD(mdwe, stock)
+{
+ .enabled = false,
+ .forked = false,
+};
+
+FIXTURE_VARIANT_ADD(mdwe, enabled)
+{
+ .enabled = true,
+ .forked = false,
+};
+
+FIXTURE_VARIANT_ADD(mdwe, forked)
+{
+ .enabled = true,
+ .forked = true,
+};
+
+FIXTURE_SETUP(mdwe)
+{
+ int ret, status;
+
+ self->p = NULL;
+ self->flags = MAP_SHARED | MAP_ANONYMOUS;
+ self->size = getpagesize();
+
+ if (!variant->enabled)
+ return;
+
+ ret = prctl(PR_SET_MDWE, PR_MDWE_REFUSE_EXEC_GAIN, 0L, 0L, 0L);
+ ASSERT_EQ(ret, 0) {
+ TH_LOG("PR_SET_MDWE failed or unsupported");
+ }
+
+ ret = prctl(PR_GET_MDWE, 0L, 0L, 0L, 0L);
+ ASSERT_EQ(ret, 1);
+
+ if (variant->forked) {
+ self->pid = fork();
+ ASSERT_GE(self->pid, 0) {
+ TH_LOG("fork failed\n");
+ }
+
+ if (self->pid > 0) {
+ ret = waitpid(self->pid, &status, 0);
+ ASSERT_TRUE(WIFEXITED(status));
+ exit(WEXITSTATUS(status));
+ }
+ }
+}
+
+FIXTURE_TEARDOWN(mdwe)
+{
+ if (self->p && self->p != MAP_FAILED)
+ munmap(self->p, self->size);
+}
+
+TEST_F(mdwe, mmap_READ_EXEC)
+{
+ self->p = mmap(NULL, self->size, PROT_READ | PROT_EXEC, self->flags, 0, 0);
+ EXPECT_NE(self->p, MAP_FAILED);
+}
+
+TEST_F(mdwe, mmap_WRITE_EXEC)
+{
+ self->p = mmap(NULL, self->size, PROT_WRITE | PROT_EXEC, self->flags, 0, 0);
+ if (variant->enabled) {
+ EXPECT_EQ(self->p, MAP_FAILED);
+ } else {
+ EXPECT_NE(self->p, MAP_FAILED);
+ }
+}
+
+TEST_F(mdwe, mprotect_stay_EXEC)
+{
+ int ret;
+
+ self->p = mmap(NULL, self->size, PROT_READ | PROT_EXEC, self->flags, 0, 0);
+ ASSERT_NE(self->p, MAP_FAILED);
+
+ ret = mprotect(self->p, self->size, PROT_READ | PROT_EXEC);
+ EXPECT_EQ(ret, 0);
+}
+
+TEST_F(mdwe, mprotect_add_EXEC)
+{
+ int ret;
+
+ self->p = mmap(NULL, self->size, PROT_READ, self->flags, 0, 0);
+ ASSERT_NE(self->p, MAP_FAILED);
+
+ ret = mprotect(self->p, self->size, PROT_READ | PROT_EXEC);
+ if (variant->enabled) {
+ EXPECT_LT(ret, 0);
+ } else {
+ EXPECT_EQ(ret, 0);
+ }
+}
+
+TEST_F(mdwe, mprotect_WRITE_EXEC)
+{
+ int ret;
+
+ self->p = mmap(NULL, self->size, PROT_WRITE, self->flags, 0, 0);
+ ASSERT_NE(self->p, MAP_FAILED);
+
+ ret = mprotect(self->p, self->size, PROT_WRITE | PROT_EXEC);
+ if (variant->enabled) {
+ EXPECT_LT(ret, 0);
+ } else {
+ EXPECT_EQ(ret, 0);
+ }
+}
+
+TEST_F(mdwe, mmap_FIXED)
+{
+ void *p, *p2;
+
+ p2 = mmap(NULL, self->size, PROT_READ | PROT_EXEC, self->flags, 0, 0);
+ self->p = mmap(NULL, self->size, PROT_READ, self->flags, 0, 0);
+ ASSERT_NE(self->p, MAP_FAILED);
+
+ p = mmap(self->p + self->size, self->size, PROT_READ | PROT_EXEC,
+ self->flags | MAP_FIXED, 0, 0);
+ if (variant->enabled) {
+ EXPECT_EQ(p, MAP_FAILED);
+ } else {
+ EXPECT_EQ(p, self->p);
+ }
+}
+
+TEST_F(mdwe, arm64_BTI)
+{
+ int ret;
+
+#ifdef __aarch64__
+ if (!(getauxval(AT_HWCAP2) & HWCAP2_BTI))
+#endif
+ SKIP(return, "HWCAP2_BTI not supported");
+
+ self->p = mmap(NULL, self->size, PROT_EXEC, self->flags, 0, 0);
+ ASSERT_NE(self->p, MAP_FAILED);
+
+ ret = mprotect(self->p, self->size, PROT_EXEC | PROT_BTI);
+ EXPECT_EQ(ret, 0);
+}
+
+TEST_HARNESS_MAIN
_
Patches currently in -mm which might be from keescook@xxxxxxxxxxxx are
kselftest-vm-add-tests-for-memory-deny-write-execute.patch
