kselftest: vm: add tests for memory-deny-write-execute

Add some tests to cover the new PR_SET_MDWE prctl.

Link: https://lkml.kernel.org/r/20230119160344.54358-3-joey.gouly@arm.com
Co-developed-by: Joey Gouly <joey.gouly@arm.com>
Signed-off-by: Joey Gouly <joey.gouly@arm.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Jeremy Linton <jeremy.linton@arm.com>
Cc: Lennart Poettering <lennart@poettering.net>
Cc: Mark Brown <broonie@kernel.org>
Cc: nd <nd@arm.com>
Cc: Szabolcs Nagy <szabolcs.nagy@arm.com>
Cc: Topi Miettinen <toiwoton@gmail.com>
Cc: Zbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl>
Cc: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Kees Cook 2023-01-19 16:03:44 +00:00 committed by Andrew Morton
parent b507808ebc
commit 4cf1fe34fd
2 changed files with 198 additions and 0 deletions

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@ -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)

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@ -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