Unverified Commit 644a7285 authored by Tahera Fahimi's avatar Tahera Fahimi Committed by Mickaël Salaün
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selftests/landlock: Test inherited restriction of abstract UNIX socket 



A socket can be shared between multiple processes, so it can connect and
send data to them. Provide a test scenario where a sandboxed process
inherits a socket's file descriptor. The process cannot connect or send
data to the inherited socket since the process is scoped.

Test coverage for security/landlock is 92.0% of 1013 lines according to
gcc/gcov-14.

Signed-off-by: default avatarTahera Fahimi <fahimitahera@gmail.com>
Link: https://lore.kernel.org/r/1428574deec13603b6ab2f2ed68ecbfa3b63bcb3.1725494372.git.fahimitahera@gmail.com


[mic: Remove negative ASSERT, fix potential race condition because of
closed connections, remove useless buffer, add test coverage]
Signed-off-by: default avatarMickaël Salaün <mic@digikod.net>
parent d1cc0ef8

tools/testing/selftests/landlock/scoped_abstract_unix_test.c

+64 −0
Original line number Diff line number Diff line
@@ -974,4 +974,68 @@ TEST(datagram_sockets) 
		_metadata->exit_code = KSFT_FAIL;

}



TEST(self_connect)

{

	struct service_fixture connected_addr, non_connected_addr;

	int connected_socket, non_connected_socket, status;

	pid_t child;



	drop_caps(_metadata);

	memset(&connected_addr, 0, sizeof(connected_addr));

	set_unix_address(&connected_addr, 0);

	memset(&non_connected_addr, 0, sizeof(non_connected_addr));

	set_unix_address(&non_connected_addr, 1);



	connected_socket = socket(AF_UNIX, SOCK_DGRAM, 0);

	non_connected_socket = socket(AF_UNIX, SOCK_DGRAM, 0);

	ASSERT_LE(0, connected_socket);

	ASSERT_LE(0, non_connected_socket);



	ASSERT_EQ(0, bind(connected_socket, &connected_addr.unix_addr,

			  connected_addr.unix_addr_len));

	ASSERT_EQ(0, bind(non_connected_socket, &non_connected_addr.unix_addr,

			  non_connected_addr.unix_addr_len));



	child = fork();

	ASSERT_LE(0, child);

	if (child == 0) {

		/* Child's domain is scoped. */

		create_scoped_domain(_metadata,

				     LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET);



		/*

		 * The child inherits the sockets, and cannot connect or

		 * send data to them.

		 */

		ASSERT_EQ(-1,

			  connect(connected_socket, &connected_addr.unix_addr,

				  connected_addr.unix_addr_len));

		ASSERT_EQ(EPERM, errno);



		ASSERT_EQ(-1, sendto(connected_socket, ".", 1, 0,

				     &connected_addr.unix_addr,

				     connected_addr.unix_addr_len));

		ASSERT_EQ(EPERM, errno);



		ASSERT_EQ(-1, sendto(non_connected_socket, ".", 1, 0,

				     &non_connected_addr.unix_addr,

				     non_connected_addr.unix_addr_len));

		ASSERT_EQ(EPERM, errno);



		EXPECT_EQ(0, close(connected_socket));

		EXPECT_EQ(0, close(non_connected_socket));

		_exit(_metadata->exit_code);

		return;

	}



	/* Waits for all tests to finish. */

	ASSERT_EQ(child, waitpid(child, &status, 0));

	EXPECT_EQ(0, close(connected_socket));

	EXPECT_EQ(0, close(non_connected_socket));



	if (WIFSIGNALED(status) || !WIFEXITED(status) ||

	    WEXITSTATUS(status) != EXIT_SUCCESS)

		_metadata->exit_code = KSFT_FAIL;

}



TEST_HARNESS_MAIN