Re: [PATCH v13 11/11] LSM: selftests for Linux Security Module syscalls

Casey Schaufler
2023-08-23T19:10:51Z

On 8/18/2023 8:53 AM, Serge Hallyn wrote:
> On Wed, Aug 02, 2023 at 10:44:34AM -0700, Casey Schaufler wrote:
>> Add selftests for the three system calls supporting the LSM
>> infrastructure. This set of tests is limited by the differences
>> in access policy enforced by the existing security modules.
>>
>> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
> I know these are just testcases, but a few things stood out below.
>
> The actual set of tests looks good, though. Thanks.
>
>> ---
>> MAINTAINERS | 1 +
>> tools/testing/selftests/Makefile | 1 +
>> tools/testing/selftests/lsm/Makefile | 19 ++
>> tools/testing/selftests/lsm/common.c | 81 ++++++
>> tools/testing/selftests/lsm/common.h | 33 +++
>> tools/testing/selftests/lsm/config | 3 +
>> .../selftests/lsm/lsm_get_self_attr_test.c | 240 ++++++++++++++++++
>> .../selftests/lsm/lsm_list_modules_test.c | 140 ++++++++++
>> .../selftests/lsm/lsm_set_self_attr_test.c | 74 ++++++
>> 9 files changed, 592 insertions(+)
>> create mode 100644 tools/testing/selftests/lsm/Makefile
>> create mode 100644 tools/testing/selftests/lsm/common.c
>> create mode 100644 tools/testing/selftests/lsm/common.h
>> create mode 100644 tools/testing/selftests/lsm/config
>> create mode 100644 tools/testing/selftests/lsm/lsm_get_self_attr_test.c
>> create mode 100644 tools/testing/selftests/lsm/lsm_list_modules_test.c
>> create mode 100644 tools/testing/selftests/lsm/lsm_set_self_attr_test.c
>>
>> diff --git a/MAINTAINERS b/MAINTAINERS
>> index aca4db11dd02..c96f1c388d22 100644
>> --- a/MAINTAINERS
>> +++ b/MAINTAINERS
>> @@ -19158,6 +19158,7 @@ W: http://kernsec.org/
>> T: git git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm.git
>> F: include/uapi/linux/lsm.h
>> F: security/
>> +F: tools/testing/selftests/lsm/
>> X: security/selinux/
>>
>> SELINUX SECURITY MODULE
>> diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile
>> index 666b56f22a41..bde7c217b23f 100644
>> --- a/tools/testing/selftests/Makefile
>> +++ b/tools/testing/selftests/Makefile
>> @@ -39,6 +39,7 @@ TARGETS += landlock
>> TARGETS += lib
>> TARGETS += livepatch
>> TARGETS += lkdtm
>> +TARGETS += lsm
>> TARGETS += membarrier
>> TARGETS += memfd
>> TARGETS += memory-hotplug
>> diff --git a/tools/testing/selftests/lsm/Makefile b/tools/testing/selftests/lsm/Makefile
>> new file mode 100644
>> index 000000000000..bae6c1e3bba4
>> --- /dev/null
>> +++ b/tools/testing/selftests/lsm/Makefile
>> @@ -0,0 +1,19 @@
>> +# SPDX-License-Identifier: GPL-2.0
>> +#
>> +# First run: make -C ../../../.. headers_install
>> +
>> +CFLAGS += -Wall -O2 $(KHDR_INCLUDES)
>> +LOCAL_HDRS += common.h
>> +
>> +TEST_GEN_PROGS := lsm_get_self_attr_test lsm_list_modules_test \
>> + lsm_set_self_attr_test
>> +
>> +include ../lib.mk
>> +
>> +$(TEST_GEN_PROGS):
>> +
>> +$(OUTPUT)/lsm_get_self_attr_test: lsm_get_self_attr_test.c common.c
>> +$(OUTPUT)/lsm_set_self_attr_test: lsm_set_self_attr_test.c common.c
>> +$(OUTPUT)/lsm_list_modules_test: lsm_list_modules_test.c common.c
>> +
>> +EXTRA_CLEAN = $(OUTPUT)/common.o
>> diff --git a/tools/testing/selftests/lsm/common.c b/tools/testing/selftests/lsm/common.c
>> new file mode 100644
>> index 000000000000..db9af9375238
>> --- /dev/null
>> +++ b/tools/testing/selftests/lsm/common.c
>> @@ -0,0 +1,81 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/*
>> + * Linux Security Module infrastructure tests
>> + *
>> + * Copyright © 2023 Casey Schaufler <casey@schaufler-ca.com>
>> + */
>> +
>> +#define _GNU_SOURCE
>> +#include <linux/lsm.h>
>> +#include <fcntl.h>
>> +#include <string.h>
>> +#include <stdio.h>
>> +#include <stdlib.h>
>> +#include <unistd.h>
>> +#include <sys/types.h>
>> +#include "common.h"
>> +
>> +#define PROCATTR "/proc/self/attr/"
>> +
>> +int read_proc_attr(const char *attr, char *value, size_t size)
>> +{
>> + int fd;
>> + int len;
>> + char *path;
>> +
>> + len = strlen(PROCATTR) + strlen(attr) + 1;
>> + path = calloc(len, 1);
>> + if (path == NULL)
>> + return -1;
>> + sprintf(path, "%s%s", PROCATTR, attr);
>> +
>> + fd = open(path, O_RDONLY);
>> + free(path);
>> +
>> + if (fd < 0)
> not closing fd here

The open failed. Nothing to close.

>
>> + return -1;
>> + len = read(fd, value, size);
>> + if (len <= 0)
>> + return -1;
>> + close(fd);
>> +
> It would feel cozier if you would ensure a trailing \0 in
> value before doing strchr.

Sure.

>
>> + path = strchr(value, '\n');
>> + if (path)
>> + *path = '\0';
>> +
>> + return 0;
>> +}
>> +
>> +int read_sysfs_lsms(char *lsms, size_t size)
>> +{
>> + FILE *fp;
>> +
>> + fp = fopen("/sys/kernel/security/lsm", "r");
>> + if (fp == NULL)
>> + return -1;
>> + if (fread(lsms, 1, size, fp) <= 0)
> not closing fp

This one does need closing.

>
>> + return -1;
>> + fclose(fp);
>> + return 0;
>> +}
>> +
>> +int attr_lsm_count(void)
>> +{
>> + char *names = calloc(sysconf(_SC_PAGESIZE), 1);
>> + int count = 0;
>> +
>> + if (!names)
>> + return 0;
>> +
>> + if (read_sysfs_lsms(names, sysconf(_SC_PAGESIZE)))
>> + return 0;
>> +
> Again strstr without ensuring \0. /sys/kernel/security/lsm
> is unlikely to be longer than _SC_PAGESIZE, but I *could*
> mess with you with a bind mount...

Because of your demonstrated cunning I will address this.

>
>> + if (strstr(names, "selinux"))
>> + count++;
>> + if (strstr(names, "smack"))
>> + count++;
>> + if (strstr(names, "apparmor"))
>> + count++;
>> +
>> + return count;
>> +}
>> diff --git a/tools/testing/selftests/lsm/common.h b/tools/testing/selftests/lsm/common.h
>> new file mode 100644
>> index 000000000000..cd0214a3eeb2
>> --- /dev/null
>> +++ b/tools/testing/selftests/lsm/common.h
>> @@ -0,0 +1,33 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/*
>> + * Linux Security Module infrastructure tests
>> + *
>> + * Copyright © 2023 Casey Schaufler <casey@schaufler-ca.com>
>> + */
>> +
>> +#ifndef lsm_get_self_attr
>> +static inline int lsm_get_self_attr(unsigned int attr, struct lsm_ctx *ctx,
>> + size_t *size, __u32 flags)
>> +{
>> + return syscall(__NR_lsm_get_self_attr, attr, ctx, size, flags);
>> +}
>> +#endif
>> +
>> +#ifndef lsm_set_self_attr
>> +static inline int lsm_set_self_attr(unsigned int attr, struct lsm_ctx *ctx,
>> + size_t size, __u32 flags)
>> +{
>> + return syscall(__NR_lsm_set_self_attr, attr, ctx, size, flags);
>> +}
>> +#endif
>> +
>> +#ifndef lsm_list_modules
>> +static inline int lsm_list_modules(__u64 *ids, size_t *size, __u32 flags)
>> +{
>> + return syscall(__NR_lsm_list_modules, ids, size, flags);
>> +}
>> +#endif
>> +
>> +extern int read_proc_attr(const char *attr, char *value, size_t size);
>> +extern int read_sysfs_lsms(char *lsms, size_t size);
>> +int attr_lsm_count(void);
>> diff --git a/tools/testing/selftests/lsm/config b/tools/testing/selftests/lsm/config
>> new file mode 100644
>> index 000000000000..1c0c4c020f9c
>> --- /dev/null
>> +++ b/tools/testing/selftests/lsm/config
>> @@ -0,0 +1,3 @@
>> +CONFIG_SYSFS=y
>> +CONFIG_SECURITY=y
>> +CONFIG_SECURITYFS=y
>> diff --git a/tools/testing/selftests/lsm/lsm_get_self_attr_test.c b/tools/testing/selftests/lsm/lsm_get_self_attr_test.c
>> new file mode 100644
>> index 000000000000..74c65aae1fcc
>> --- /dev/null
>> +++ b/tools/testing/selftests/lsm/lsm_get_self_attr_test.c
>> @@ -0,0 +1,240 @@
>> +// 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);
>> + size_t size = page_size;
>> +
>> + ASSERT_NE(NULL, ctx);
>> + errno = 0;
>> + ASSERT_EQ(-1, lsm_get_self_attr(LSM_ATTR_CURRENT, ctx, &size, 1));
>> + ASSERT_EQ(EINVAL, errno);
>> + ASSERT_EQ(page_size, size);
>> +
>> + 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 = page_size;
>> +
>> + ASSERT_NE(NULL, ctx);
>> + errno = 0;
>> + ASSERT_EQ(-1, lsm_get_self_attr(LSM_ATTR_CURRENT | LSM_ATTR_PREV, ctx,
>> + &size, 0));
>> + ASSERT_EQ(EOPNOTSUPP, 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);
> You never verify attr is not NULL

True. Will fix.

>
>> + 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
>> diff --git a/tools/testing/selftests/lsm/lsm_list_modules_test.c b/tools/testing/selftests/lsm/lsm_list_modules_test.c
>> new file mode 100644
>> index 000000000000..445c02f09c74
>> --- /dev/null
>> +++ b/tools/testing/selftests/lsm/lsm_list_modules_test.c
>> @@ -0,0 +1,140 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/*
>> + * Linux Security Module infrastructure tests
>> + * Tests for the lsm_list_modules system call
>> + *
>> + * Copyright © 2022 Casey Schaufler <casey@schaufler-ca.com>
>> + */
>> +
>> +#define _GNU_SOURCE
>> +#include <linux/lsm.h>
>> +#include <string.h>
>> +#include <stdio.h>
>> +#include <unistd.h>
>> +#include <sys/types.h>
>> +#include "../kselftest_harness.h"
>> +#include "common.h"
>> +
>> +TEST(size_null_lsm_list_modules)
>> +{
>> + const long page_size = sysconf(_SC_PAGESIZE);
>> + __u64 *syscall_lsms = calloc(page_size, 1);
>> +
>> + ASSERT_NE(NULL, syscall_lsms);
>> + errno = 0;
>> + ASSERT_EQ(-1, lsm_list_modules(syscall_lsms, NULL, 0));
>> + ASSERT_EQ(EFAULT, errno);
>> +
>> + free(syscall_lsms);
>> +}
>> +
>> +TEST(ids_null_lsm_list_modules)
>> +{
>> + const long page_size = sysconf(_SC_PAGESIZE);
>> + size_t size = page_size;
>> +
>> + errno = 0;
>> + ASSERT_EQ(-1, lsm_list_modules(NULL, &size, 0));
>> + ASSERT_EQ(EFAULT, errno);
>> + ASSERT_NE(1, size);
>> +}
>> +
>> +TEST(size_too_small_lsm_list_modules)
>> +{
>> + const long page_size = sysconf(_SC_PAGESIZE);
>> + __u64 *syscall_lsms = calloc(page_size, 1);
>> + size_t size = 1;
>> +
>> + ASSERT_NE(NULL, syscall_lsms);
>> + errno = 0;
>> + ASSERT_EQ(-1, lsm_list_modules(syscall_lsms, &size, 0));
>> + ASSERT_EQ(E2BIG, errno);
>> + ASSERT_NE(1, size);
>> +
>> + free(syscall_lsms);
>> +}
>> +
>> +TEST(flags_set_lsm_list_modules)
>> +{
>> + const long page_size = sysconf(_SC_PAGESIZE);
>> + __u64 *syscall_lsms = calloc(page_size, 1);
>> + size_t size = page_size;
>> +
>> + ASSERT_NE(NULL, syscall_lsms);
>> + errno = 0;
>> + ASSERT_EQ(-1, lsm_list_modules(syscall_lsms, &size, 7));
>> + ASSERT_EQ(EINVAL, errno);
>> + ASSERT_EQ(page_size, size);
>> +
>> + free(syscall_lsms);
>> +}
>> +
>> +TEST(correct_lsm_list_modules)
>> +{
>> + const long page_size = sysconf(_SC_PAGESIZE);
>> + size_t size = page_size;
>> + __u64 *syscall_lsms = calloc(page_size, 1);
>> + char *sysfs_lsms = calloc(page_size, 1);
>> + char *name;
>> + char *cp;
>> + int count;
>> + int i;
>> +
>> + ASSERT_NE(NULL, sysfs_lsms);
>> + ASSERT_NE(NULL, syscall_lsms);
>> + ASSERT_EQ(0, read_sysfs_lsms(sysfs_lsms, page_size));
>> +
>> + count = lsm_list_modules(syscall_lsms, &size, 0);
>> + ASSERT_LE(1, count);
>> + cp = sysfs_lsms;
>> + for (i = 0; i < count; i++) {
>> + switch (syscall_lsms[i]) {
>> + case LSM_ID_CAPABILITY:
>> + name = "capability";
>> + break;
>> + case LSM_ID_SELINUX:
>> + name = "selinux";
>> + break;
>> + case LSM_ID_SMACK:
>> + name = "smack";
>> + break;
>> + case LSM_ID_TOMOYO:
>> + name = "tomoyo";
>> + break;
>> + case LSM_ID_IMA:
>> + name = "ima";
>> + break;
>> + case LSM_ID_APPARMOR:
>> + name = "apparmor";
>> + break;
>> + case LSM_ID_YAMA:
>> + name = "yama";
>> + break;
>> + case LSM_ID_LOADPIN:
>> + name = "loadpin";
>> + break;
>> + case LSM_ID_SAFESETID:
>> + name = "safesetid";
>> + break;
>> + case LSM_ID_LOCKDOWN:
>> + name = "lockdown";
>> + break;
>> + case LSM_ID_BPF:
>> + name = "bpf";
>> + break;
>> + case LSM_ID_LANDLOCK:
>> + name = "landlock";
>> + break;
>> + default:
>> + name = "INVALID";
>> + break;
>> + }
>> + ASSERT_EQ(0, strncmp(cp, name, strlen(name)));
>> + cp += strlen(name) + 1;
>> + }
>> +
>> + free(sysfs_lsms);
>> + free(syscall_lsms);
>> +}
>> +
>> +TEST_HARNESS_MAIN
>> diff --git a/tools/testing/selftests/lsm/lsm_set_self_attr_test.c b/tools/testing/selftests/lsm/lsm_set_self_attr_test.c
>> new file mode 100644
>> index 000000000000..d0f5b776c548
>> --- /dev/null
>> +++ b/tools/testing/selftests/lsm/lsm_set_self_attr_test.c
>> @@ -0,0 +1,74 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/*
>> + * Linux Security Module infrastructure tests
>> + * Tests for the lsm_set_self_attr system call
>> + *
>> + * Copyright © 2022 Casey Schaufler <casey@schaufler-ca.com>
>> + */
>> +
>> +#define _GNU_SOURCE
>> +#include <linux/lsm.h>
>> +#include <string.h>
>> +#include <stdio.h>
>> +#include <unistd.h>
>> +#include <sys/types.h>
>> +#include "../kselftest_harness.h"
>> +#include "common.h"
>> +
>> +TEST(ctx_null_lsm_set_self_attr)
>> +{
>> + ASSERT_EQ(-1, lsm_set_self_attr(LSM_ATTR_CURRENT, NULL,
>> + sizeof(struct lsm_ctx), 0));
>> +}
>> +
>> +TEST(size_too_small_lsm_set_self_attr)
>> +{
>> + const long page_size = sysconf(_SC_PAGESIZE);
>> + struct lsm_ctx *ctx = calloc(page_size, 1);
>> + size_t size = page_size;
>> +
>> + ASSERT_NE(NULL, ctx);
>> + if (attr_lsm_count()) {
>> + ASSERT_LE(1, lsm_get_self_attr(LSM_ATTR_CURRENT, ctx, &size,
>> + 0));
>> + }
>> + ASSERT_EQ(-1, lsm_set_self_attr(LSM_ATTR_CURRENT, ctx, 1, 0));
>> +
>> + free(ctx);
>> +}
>> +
>> +TEST(flags_zero_lsm_set_self_attr)
>> +{
>> + const long page_size = sysconf(_SC_PAGESIZE);
>> + struct lsm_ctx *ctx = calloc(page_size, 1);
>> + size_t size = page_size;
>> +
>> + ASSERT_NE(NULL, ctx);
>> + if (attr_lsm_count()) {
>> + ASSERT_LE(1, lsm_get_self_attr(LSM_ATTR_CURRENT, ctx, &size,
>> + 0));
>> + }
>> + ASSERT_EQ(-1, lsm_set_self_attr(LSM_ATTR_CURRENT, ctx, size, 1));
>> +
>> + free(ctx);
>> +}
>> +
>> +TEST(flags_overset_lsm_set_self_attr)
>> +{
>> + const long page_size = sysconf(_SC_PAGESIZE);
>> + char *ctx = calloc(page_size, 1);
>> + size_t size = page_size;
>> + struct lsm_ctx *tctx = (struct lsm_ctx *)ctx;
>> +
>> + ASSERT_NE(NULL, ctx);
>> + if (attr_lsm_count()) {
>> + ASSERT_LE(1, lsm_get_self_attr(LSM_ATTR_CURRENT, tctx, &size,
>> + 0));
>> + }
>> + ASSERT_EQ(-1, lsm_set_self_attr(LSM_ATTR_CURRENT | LSM_ATTR_PREV, tctx,
>> + size, 0));
>> +
>> + free(ctx);
>> +}
>> +
>> +TEST_HARNESS_MAIN
>> --
>> 2.41.0
>>
>>