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selftests/landlock: Test inherited restriction of abstract UNIX socket

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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: Tahera 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: Mickaël Salaün <mic@digikod.net>
This commit is contained in:
Tahera Fahimi 2024-09-04 18:14:00 -06:00 committed by Mickaël Salaün
parent d1cc0ef80f
commit 644a728506
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1 changed files with 64 additions and 0 deletions
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64
tools/testing/selftests/landlock/scoped_abstract_unix_test.c
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@ -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