[PATCH v8 10/12] selftests/landlock: Add 10 new test suites dedicated to network
Mickaël Salaün
mic at digikod.net
Mon Jan 9 12:46:29 UTC 2023
On 21/10/2022 17:26, Konstantin Meskhidze wrote:
> These test suites try to check edge cases for TCP sockets
> bind() and connect() actions.
>
> socket:
> * bind_no_restrictions: Tests with non-landlocked ipv4 and ipv6 sockets.
> * bind_with_restrictions: Tests with mixed landlock rules for ipv4 and
> ipv6 sockets.
> * connect_no_restrictions: Tests with non-landlocked ipv4 and ipv6 sockets.
> * connect_with_restrictions: Tests with mixed landlock rules for ipv4 and
> ipv6 sockets.
> * connect_afunspec_no_restrictions: Tests with no landlock restrictions
> allowing to disconnect already connected socket with AF_UNSPEC socket
> family.
> * connect_afunspec_with_restrictions: Tests with landlocked process
> refusing to disconnect already connected socket.
> * ruleset_overlap: Tests with overlapping rules for one port.
> * ruleset_expanding: Tests with expanding rulesets in which rules are
> gradually added one by one, restricting sockets' connections.
> * inval: Tests with invalid user space supplied data:
> - out of range ruleset attribute;
> - unhandled allowed access;
> - zero port value;
> - zero access value;
> - legitimate access values;
>
> layout1:
> * with_net: Tests with network bind() socket action within
> filesystem directory access test.
>
> Test coverage for security/landlock is 94.3% of 920 lines according
> to gcc/gcov-11.
>
> Signed-off-by: Konstantin Meskhidze <konstantin.meskhidze at huawei.com>
> ---
>
> Changes since v7:
> * Squashes all selftest commits.
> * Adds fs test with network bind() socket action.
> * Minor fixes.
>
> ---
> security/landlock/ruleset.h | 2 -
> tools/testing/selftests/landlock/config | 4 +
> tools/testing/selftests/landlock/fs_test.c | 65 ++
> tools/testing/selftests/landlock/net_test.c | 823 ++++++++++++++++++++
> 4 files changed, 892 insertions(+), 2 deletions(-)
> create mode 100644 tools/testing/selftests/landlock/net_test.c
>
> diff --git a/security/landlock/ruleset.h b/security/landlock/ruleset.h
> index f272d2cd518c..ee1a02a404ce 100644
> --- a/security/landlock/ruleset.h
> +++ b/security/landlock/ruleset.h
> @@ -264,7 +264,6 @@ landlock_add_fs_access_mask(struct landlock_ruleset *const ruleset,
>
> /* Should already be checked in sys_landlock_create_ruleset(). */
> WARN_ON_ONCE(fs_access_mask != fs_mask);
> - // TODO: Add tests to check "|=" and not "="
> ruleset->access_masks[layer_level] |=
> (fs_mask << LANDLOCK_SHIFT_ACCESS_FS);
> }
> @@ -278,7 +277,6 @@ landlock_add_net_access_mask(struct landlock_ruleset *const ruleset,
>
> /* Should already be checked in sys_landlock_create_ruleset(). */
> WARN_ON_ONCE(net_access_mask != net_mask);
> - // TODO: Add tests to check "|=" and not "="
> ruleset->access_masks[layer_level] |=
> (net_mask << LANDLOCK_SHIFT_ACCESS_NET);
> }
> diff --git a/tools/testing/selftests/landlock/config b/tools/testing/selftests/landlock/config
> index 0f0a65287bac..71f7e9a8a64c 100644
> --- a/tools/testing/selftests/landlock/config
> +++ b/tools/testing/selftests/landlock/config
> @@ -1,3 +1,7 @@
> +CONFIG_INET=y
> +CONFIG_IPV6=y
> +CONFIG_NET=y
> +CONFIG_NET_NS=y
> CONFIG_OVERLAY_FS=y
> CONFIG_SECURITY_LANDLOCK=y
> CONFIG_SECURITY_PATH=y
> diff --git a/tools/testing/selftests/landlock/fs_test.c b/tools/testing/selftests/landlock/fs_test.c
> index 20c1ac8485f1..5c52da1a5a69 100644
> --- a/tools/testing/selftests/landlock/fs_test.c
> +++ b/tools/testing/selftests/landlock/fs_test.c
> @@ -8,14 +8,17 @@
> */
>
> #define _GNU_SOURCE
> +#include <arpa/inet.h>
> #include <fcntl.h>
> #include <linux/landlock.h>
> +#include <netinet/in.h>
> #include <sched.h>
> #include <string.h>
> #include <sys/capability.h>
> #include <sys/mount.h>
> #include <sys/prctl.h>
> #include <sys/sendfile.h>
> +#include <sys/socket.h>
> #include <sys/stat.h>
> #include <sys/sysmacros.h>
> #include <unistd.h>
> @@ -4366,4 +4369,66 @@ TEST_F_FORK(layout2_overlay, same_content_different_file)
> }
> }
>
> +#define IP_ADDRESS "127.0.0.1"
> +
> +TEST_F_FORK(layout1, with_net)
> +{
> + int sockfd;
> + int sock_port = 15000;
> + struct sockaddr_in addr4;
> +
> + addr4.sin_family = AF_INET;
> + addr4.sin_port = htons(sock_port);
> + addr4.sin_addr.s_addr = inet_addr(IP_ADDRESS);
> + memset(&addr4.sin_zero, '\0', 8);
> +
> + const struct rule rules[] = {
> + {
> + .path = dir_s1d2,
> + .access = ACCESS_RO,
> + },
> + {},
> + };
> +
> + struct landlock_ruleset_attr ruleset_attr_net = {
> + .handled_access_net = LANDLOCK_ACCESS_NET_BIND_TCP |
> + LANDLOCK_ACCESS_NET_CONNECT_TCP,
> + };
> + struct landlock_net_service_attr net_service = {
> + .allowed_access = LANDLOCK_ACCESS_NET_BIND_TCP,
> +
> + .port = sock_port,
> + };
> +
> + /* Creates ruleset for network access. */
> + const int ruleset_fd_net = landlock_create_ruleset(
> + &ruleset_attr_net, sizeof(ruleset_attr_net), 0);
> + ASSERT_LE(0, ruleset_fd_net);
> +
> + /* Adds a network rule. */
> + ASSERT_EQ(0,
> + landlock_add_rule(ruleset_fd_net, LANDLOCK_RULE_NET_SERVICE,
> + &net_service, 0));
> +
> + enforce_ruleset(_metadata, ruleset_fd_net);
> + ASSERT_EQ(0, close(ruleset_fd_net));
> +
> + const int ruleset_fd = create_ruleset(_metadata, ACCESS_RW, rules);
> + ASSERT_LE(0, ruleset_fd);
> + enforce_ruleset(_metadata, ruleset_fd);
> + ASSERT_EQ(0, close(ruleset_fd));
> +
> + /* Tests on a directory with the network rule loaded. */
> + ASSERT_EQ(0, test_open(dir_s1d2, O_RDONLY));
> + ASSERT_EQ(0, test_open(file1_s1d2, O_RDONLY));
> +
> + sockfd = socket(AF_INET, SOCK_STREAM | SOCK_CLOEXEC, 0);
> + ASSERT_LE(0, sockfd);
> + /* Binds a socket to port 15000. */
> + ASSERT_EQ(0, bind(sockfd, &addr4, sizeof(addr4)));
> +
> + /* Closes bounded socket. */
> + ASSERT_EQ(0, close(sockfd));
> +}
> +
> TEST_HARNESS_MAIN
> diff --git a/tools/testing/selftests/landlock/net_test.c b/tools/testing/selftests/landlock/net_test.c
> new file mode 100644
> index 000000000000..d1548bd7ab60
> --- /dev/null
> +++ b/tools/testing/selftests/landlock/net_test.c
> @@ -0,0 +1,823 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Landlock tests - Network
> + *
> + * Copyright (C) 2022 Huawei Tech. Co., Ltd.
> + */
> +
> +#define _GNU_SOURCE
> +#include <arpa/inet.h>
> +#include <errno.h>
> +#include <fcntl.h>
> +#include <linux/landlock.h>
> +#include <netinet/in.h>
> +#include <sched.h>
> +#include <string.h>
> +#include <sys/prctl.h>
> +#include <sys/socket.h>
> +#include <sys/types.h>
> +
> +#include "common.h"
> +
> +#define MAX_SOCKET_NUM 10
> +
> +#define SOCK_PORT_START 3470
> +#define SOCK_PORT_ADD 10
> +
> +#define IP_ADDRESS "127.0.0.1"
> +
> +/* Number pending connections queue to be hold. */
> +#define BACKLOG 10
> +
> +const struct sockaddr addr_unspec = { .sa_family = AF_UNSPEC };
> +
> +/* Invalid attribute, out of landlock network access range. */
> +#define LANDLOCK_INVAL_ATTR 7
> +
> +FIXTURE(socket)
> +{
> + uint port[MAX_SOCKET_NUM];
> + struct sockaddr_in addr4[MAX_SOCKET_NUM];
> + struct sockaddr_in6 addr6[MAX_SOCKET_NUM];
> +};
> +
> +/* struct _fixture_variant_socket */
> +FIXTURE_VARIANT(socket)
> +{
> + const bool is_ipv4;
> +};
> +
> +/* clang-format off */
> +FIXTURE_VARIANT_ADD(socket, ipv4) {
> + /* clang-format on */
> + .is_ipv4 = true,
> +};
> +
> +/* clang-format off */
> +FIXTURE_VARIANT_ADD(socket, ipv6) {
> + /* clang-format on */
> + .is_ipv4 = false,
> +};
> +
> +static int
> +create_socket_variant(const struct _fixture_variant_socket *const variant,
> + const int type)
> +{
> + if (variant->is_ipv4)
> + return socket(AF_INET, type | SOCK_CLOEXEC, 0);
> + else
> + return socket(AF_INET6, type | SOCK_CLOEXEC, 0);
> +}
> +
> +static int bind_variant(const struct _fixture_variant_socket *const variant,
> + const int sockfd,
> + const struct _test_data_socket *const self,
> + const size_t index)
> +{
> + if (variant->is_ipv4)
> + return bind(sockfd, &self->addr4[index],
> + sizeof(self->addr4[index]));
> + else
> + return bind(sockfd, &self->addr6[index],
> + sizeof(self->addr6[index]));
> +}
> +
> +static int connect_variant(const struct _fixture_variant_socket *const variant,
> + const int sockfd,
> + const struct _test_data_socket *const self,
> + const size_t index)
> +{
> + if (variant->is_ipv4)
> + return connect(sockfd, &self->addr4[index],
> + sizeof(self->addr4[index]));
> + else
> + return connect(sockfd, &self->addr6[index],
> + sizeof(self->addr6[index]));
> +}
> +
> +FIXTURE_SETUP(socket)
> +{
> + int i;
> +
> + /* Creates IPv4 socket addresses. */
> + for (i = 0; i < MAX_SOCKET_NUM; i++) {
> + self->port[i] = SOCK_PORT_START + SOCK_PORT_ADD * i;
> + self->addr4[i].sin_family = AF_INET;
> + self->addr4[i].sin_port = htons(self->port[i]);
> + self->addr4[i].sin_addr.s_addr = inet_addr(IP_ADDRESS);
> + memset(&(self->addr4[i].sin_zero), '\0', 8);
> + }
> +
> + /* Creates IPv6 socket addresses. */
> + for (i = 0; i < MAX_SOCKET_NUM; i++) {
> + self->port[i] = SOCK_PORT_START + SOCK_PORT_ADD * i;
> + self->addr6[i].sin6_family = AF_INET6;
> + self->addr6[i].sin6_port = htons(self->port[i]);
> + inet_pton(AF_INET6, IP_ADDRESS, &(self->addr6[i].sin6_addr));
> + }
> +
> + set_cap(_metadata, CAP_SYS_ADMIN);
> + ASSERT_EQ(0, unshare(CLONE_NEWNET));
> + ASSERT_EQ(0, system("ip link set dev lo up"));
> + clear_cap(_metadata, CAP_SYS_ADMIN);
> +}
> +
> +FIXTURE_TEARDOWN(socket)
> +{
> +}
> +
> +TEST_F_FORK(socket, bind_no_restrictions)
> +{
> + int sockfd;
> +
> + sockfd = create_socket_variant(variant, SOCK_STREAM);
> + ASSERT_LE(0, sockfd);
> +
> + /* Binds a socket to port[0]. */
> + ASSERT_EQ(0, bind_variant(variant, sockfd, self, 0));
> +
> + ASSERT_EQ(0, close(sockfd));
> +}
> +
> +TEST_F_FORK(socket, bind_with_restrictions)
> +{
> + int sockfd;
> +
> + struct landlock_ruleset_attr ruleset_attr = {
> + .handled_access_net = LANDLOCK_ACCESS_NET_BIND_TCP |
> + LANDLOCK_ACCESS_NET_CONNECT_TCP,
> + };
> + struct landlock_net_service_attr net_service_1 = {
> + .allowed_access = LANDLOCK_ACCESS_NET_BIND_TCP |
> + LANDLOCK_ACCESS_NET_CONNECT_TCP,
> + .port = self->port[0],
> + };
> + struct landlock_net_service_attr net_service_2 = {
> + .allowed_access = LANDLOCK_ACCESS_NET_CONNECT_TCP,
> + .port = self->port[1],
> + };
> + struct landlock_net_service_attr net_service_3 = {
> + .allowed_access = 0,
> + .port = self->port[2],
> + };
> +
> + const int ruleset_fd =
> + landlock_create_ruleset(&ruleset_attr, sizeof(ruleset_attr), 0);
> + ASSERT_LE(0, ruleset_fd);
> +
> + /* Allows connect and bind operations to the port[0] socket. */
> + ASSERT_EQ(0, landlock_add_rule(ruleset_fd, LANDLOCK_RULE_NET_SERVICE,
> + &net_service_1, 0));
> + /* Allows connect and deny bind operations to the port[1] socket. */
> + ASSERT_EQ(0, landlock_add_rule(ruleset_fd, LANDLOCK_RULE_NET_SERVICE,
> + &net_service_2, 0));
> + /*
> + * Empty allowed_access (i.e. deny rules) are ignored in network actions
> + * for port[2] socket.
> + */
> + ASSERT_EQ(-1, landlock_add_rule(ruleset_fd, LANDLOCK_RULE_NET_SERVICE,
> + &net_service_3, 0));
> + ASSERT_EQ(ENOMSG, errno);
> +
> + /* Enforces the ruleset. */
> + enforce_ruleset(_metadata, ruleset_fd);
> +
> + sockfd = create_socket_variant(variant, SOCK_STREAM);
> + ASSERT_LE(0, sockfd);
> + /* Binds a socket to port[0]. */
> + ASSERT_EQ(0, bind_variant(variant, sockfd, self, 0));
> +
> + /* Closes bounded socket. */
> + ASSERT_EQ(0, close(sockfd));
> +
> + sockfd = create_socket_variant(variant, SOCK_STREAM);
> + ASSERT_LE(0, sockfd);
> + /* Binds a socket to port[1]. */
> + ASSERT_EQ(-1, bind_variant(variant, sockfd, self, 1));
> + ASSERT_EQ(EACCES, errno);
> +
> + sockfd = create_socket_variant(variant, SOCK_STREAM);
> + ASSERT_LE(0, sockfd);
> + /* Binds a socket to port[2]. */
> + ASSERT_EQ(-1, bind_variant(variant, sockfd, self, 2));
> + ASSERT_EQ(EACCES, errno);
This is inconsistent with the bind_no_restrictions test. If you
deduplicate the tests with and without restrictions (i.e. only one
"bind" test, and another "connect"…), you can extend
FIXTURE_VARIANT(socket) with a new const bool enforce_landlock, and
check that in all tests to either do Landlock syscalls or not. You can
still initialize most variable whatever Landlock should be enforced or
not (e.g. ruleset_attr, net_service_1…) to make it easiear to read.
> +}
> +
> +TEST_F_FORK(socket, connect_no_restrictions)
More information about the Linux-security-module-archive
mailing list