linux/tools/testing/selftests/lsm/lsm_get_self_attr_test.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Linux Security Module infrastructure tests
 * Tests for the lsm_get_self_attr system call
 *
 * Copyright © 2022 Casey Schaufler <casey@schaufler-ca.com>
 */

#define _GNU_SOURCE
#include <linux/lsm.h>
#include <fcntl.h>
#include <string.h>
#include <stdio.h>
#include <unistd.h>
#include <sys/types.h>
#include "../kselftest_harness.h"
#include "common.h"

static struct lsm_ctx *next_ctx(struct lsm_ctx *ctxp)
{
	void *vp;

	vp = (void *)ctxp + sizeof(*ctxp) + ctxp->ctx_len;
	return (struct lsm_ctx *)vp;
}

TEST(size_null_lsm_get_self_attr)
{
	const long page_size = sysconf(_SC_PAGESIZE);
	struct lsm_ctx *ctx = calloc(page_size, 1);

	ASSERT_NE(NULL, ctx);
	errno = 0;
	ASSERT_EQ(-1, lsm_get_self_attr(LSM_ATTR_CURRENT, ctx, NULL, 0));
	ASSERT_EQ(EINVAL, errno);

	free(ctx);
}

TEST(ctx_null_lsm_get_self_attr)
{
	const long page_size = sysconf(_SC_PAGESIZE);
	size_t size = page_size;
	int rc;

	rc = lsm_get_self_attr(LSM_ATTR_CURRENT, NULL, &size, 0);

	if (attr_lsm_count()) {
		ASSERT_NE(-1, rc);
		ASSERT_NE(1, size);
	} else {
		ASSERT_EQ(-1, rc);
	}
}

TEST(size_too_small_lsm_get_self_attr)
{
	const long page_size = sysconf(_SC_PAGESIZE);
	struct lsm_ctx *ctx = calloc(page_size, 1);
	size_t size = 1;

	ASSERT_NE(NULL, ctx);
	errno = 0;
	ASSERT_EQ(-1, lsm_get_self_attr(LSM_ATTR_CURRENT, ctx, &size, 0));
	if (attr_lsm_count()) {
		ASSERT_EQ(E2BIG, errno);
	} else {
		ASSERT_EQ(EOPNOTSUPP, errno);
	}
	ASSERT_NE(1, size);

	free(ctx);
}

TEST(flags_zero_lsm_get_self_attr)
{
	const long page_size = sysconf(_SC_PAGESIZE);
	struct lsm_ctx *ctx = calloc(page_size, 1);
	__u64 *syscall_lsms = calloc(page_size, 1);
	size_t size;
	int lsmcount;
	int i;

	ASSERT_NE(NULL, ctx);
	errno = 0;
	size = page_size;
	ASSERT_EQ(-1, lsm_get_self_attr(LSM_ATTR_CURRENT, ctx, &size,
					LSM_FLAG_SINGLE));
	ASSERT_EQ(EINVAL, errno);
	ASSERT_EQ(page_size, size);

	lsmcount = syscall(__NR_lsm_list_modules, syscall_lsms, &size, 0);
	ASSERT_LE(1, lsmcount);
	ASSERT_NE(NULL, syscall_lsms);

	for (i = 0; i < lsmcount; i++) {
		errno = 0;
		size = page_size;
		ctx->id = syscall_lsms[i];

		if (syscall_lsms[i] == LSM_ID_SELINUX ||
		    syscall_lsms[i] == LSM_ID_SMACK ||
		    syscall_lsms[i] == LSM_ID_APPARMOR) {
			ASSERT_EQ(1, lsm_get_self_attr(LSM_ATTR_CURRENT, ctx,
						       &size, LSM_FLAG_SINGLE));
		} else {
			ASSERT_EQ(-1, lsm_get_self_attr(LSM_ATTR_CURRENT, ctx,
							&size,
							LSM_FLAG_SINGLE));
		}
	}

	free(ctx);
}

TEST(flags_overset_lsm_get_self_attr)
{
	const long page_size = sysconf(_SC_PAGESIZE);
	struct lsm_ctx *ctx = calloc(page_size, 1);
	size_t size;

	ASSERT_NE(NULL, ctx);

	errno = 0;
	size = page_size;
	ASSERT_EQ(-1, lsm_get_self_attr(LSM_ATTR_CURRENT | LSM_ATTR_PREV, ctx,
					&size, 0));
	ASSERT_EQ(EOPNOTSUPP, errno);

	errno = 0;
	size = page_size;
	ASSERT_EQ(-1, lsm_get_self_attr(LSM_ATTR_CURRENT, ctx, &size,
					LSM_FLAG_SINGLE |
					(LSM_FLAG_SINGLE << 1)));
	ASSERT_EQ(EINVAL, errno);

	free(ctx);
}

TEST(basic_lsm_get_self_attr)
{
	const long page_size = sysconf(_SC_PAGESIZE);
	size_t size = page_size;
	struct lsm_ctx *ctx = calloc(page_size, 1);
	struct lsm_ctx *tctx = NULL;
	__u64 *syscall_lsms = calloc(page_size, 1);
	char *attr = calloc(page_size, 1);
	int cnt_current = 0;
	int cnt_exec = 0;
	int cnt_fscreate = 0;
	int cnt_keycreate = 0;
	int cnt_prev = 0;
	int cnt_sockcreate = 0;
	int lsmcount;
	int count;
	int i;

	ASSERT_NE(NULL, ctx);
	ASSERT_NE(NULL, syscall_lsms);

	lsmcount = syscall(__NR_lsm_list_modules, syscall_lsms, &size, 0);
	ASSERT_LE(1, lsmcount);

	for (i = 0; i < lsmcount; i++) {
		switch (syscall_lsms[i]) {
		case LSM_ID_SELINUX:
			cnt_current++;
			cnt_exec++;
			cnt_fscreate++;
			cnt_keycreate++;
			cnt_prev++;
			cnt_sockcreate++;
			break;
		case LSM_ID_SMACK:
			cnt_current++;
			break;
		case LSM_ID_APPARMOR:
			cnt_current++;
			cnt_exec++;
			cnt_prev++;
			break;
		default:
			break;
		}
	}

	if (cnt_current) {
		size = page_size;
		count = lsm_get_self_attr(LSM_ATTR_CURRENT, ctx, &size, 0);
		ASSERT_EQ(cnt_current, count);
		tctx = ctx;
		ASSERT_EQ(0, read_proc_attr("current", attr, page_size));
		ASSERT_EQ(0, strcmp((char *)tctx->ctx, attr));
		for (i = 1; i < count; i++) {
			tctx = next_ctx(tctx);
			ASSERT_NE(0, strcmp((char *)tctx->ctx, attr));
		}
	}
	if (cnt_exec) {
		size = page_size;
		count = lsm_get_self_attr(LSM_ATTR_EXEC, ctx, &size, 0);
		ASSERT_GE(cnt_exec, count);
		if (count > 0) {
			tctx = ctx;
			if (read_proc_attr("exec", attr, page_size) == 0)
				ASSERT_EQ(0, strcmp((char *)tctx->ctx, attr));
		}
		for (i = 1; i < count; i++) {
			tctx = next_ctx(tctx);
			ASSERT_NE(0, strcmp((char *)tctx->ctx, attr));
		}
	}
	if (cnt_fscreate) {
		size = page_size;
		count = lsm_get_self_attr(LSM_ATTR_FSCREATE, ctx, &size, 0);
		ASSERT_GE(cnt_fscreate, count);
		if (count > 0) {
			tctx = ctx;
			if (read_proc_attr("fscreate", attr, page_size) == 0)
				ASSERT_EQ(0, strcmp((char *)tctx->ctx, attr));
		}
		for (i = 1; i < count; i++) {
			tctx = next_ctx(tctx);
			ASSERT_NE(0, strcmp((char *)tctx->ctx, attr));
		}
	}
	if (cnt_keycreate) {
		size = page_size;
		count = lsm_get_self_attr(LSM_ATTR_KEYCREATE, ctx, &size, 0);
		ASSERT_GE(cnt_keycreate, count);
		if (count > 0) {
			tctx = ctx;
			if (read_proc_attr("keycreate", attr, page_size) == 0)
				ASSERT_EQ(0, strcmp((char *)tctx->ctx, attr));
		}
		for (i = 1; i < count; i++) {
			tctx = next_ctx(tctx);
			ASSERT_NE(0, strcmp((char *)tctx->ctx, attr));
		}
	}
	if (cnt_prev) {
		size = page_size;
		count = lsm_get_self_attr(LSM_ATTR_PREV, ctx, &size, 0);
		ASSERT_GE(cnt_prev, count);
		if (count > 0) {
			tctx = ctx;
			ASSERT_EQ(0, read_proc_attr("prev", attr, page_size));
			ASSERT_EQ(0, strcmp((char *)tctx->ctx, attr));
			for (i = 1; i < count; i++) {
				tctx = next_ctx(tctx);
				ASSERT_NE(0, strcmp((char *)tctx->ctx, attr));
			}
		}
	}
	if (cnt_sockcreate) {
		size = page_size;
		count = lsm_get_self_attr(LSM_ATTR_SOCKCREATE, ctx, &size, 0);
		ASSERT_GE(cnt_sockcreate, count);
		if (count > 0) {
			tctx = ctx;
			if (read_proc_attr("sockcreate", attr, page_size) == 0)
				ASSERT_EQ(0, strcmp((char *)tctx->ctx, attr));
		}
		for (i = 1; i < count; i++) {
			tctx = next_ctx(tctx);
			ASSERT_NE(0, strcmp((char *)tctx->ctx, attr));
		}
	}

	free(ctx);
	free(attr);
	free(syscall_lsms);
}

TEST_HARNESS_MAIN