selftests/landlock: Test signal scoping for threads

Expand the signal scoping tests with pthread_kill(3).  Test if a scoped
thread can send signal to a process in the same scoped domain, or a
non-sandboxed thread.

Signed-off-by: Tahera Fahimi <fahimitahera@gmail.com>
Link: https://lore.kernel.org/r/c15e9eafbb2da1210e46ba8db7b8907f5ea11009.1725657728.git.fahimitahera@gmail.com
[mic: Improve commit message]
Signed-off-by: Mickaël Salaün <mic@digikod.net>
This commit is contained in:
Tahera Fahimi 2024-09-06 15:30:05 -06:00 committed by Mickaël Salaün
parent ea292363c3
commit c899496501
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@ -9,6 +9,7 @@
#include <errno.h>
#include <fcntl.h>
#include <linux/landlock.h>
#include <pthread.h>
#include <signal.h>
#include <sys/prctl.h>
#include <sys/types.h>
@ -248,4 +249,52 @@ TEST_F(scoped_domains, check_access_signal)
_metadata->exit_code = KSFT_FAIL;
}
static int thread_pipe[2];
enum thread_return {
THREAD_INVALID = 0,
THREAD_SUCCESS = 1,
THREAD_ERROR = 2,
};
void *thread_func(void *arg)
{
char buf;
if (read(thread_pipe[0], &buf, 1) != 1)
return (void *)THREAD_ERROR;
return (void *)THREAD_SUCCESS;
}
TEST(signal_scoping_threads)
{
pthread_t no_sandbox_thread, scoped_thread;
enum thread_return ret = THREAD_INVALID;
drop_caps(_metadata);
ASSERT_EQ(0, pipe2(thread_pipe, O_CLOEXEC));
ASSERT_EQ(0,
pthread_create(&no_sandbox_thread, NULL, thread_func, NULL));
/* Restricts the domain after creating the first thread. */
create_scoped_domain(_metadata, LANDLOCK_SCOPE_SIGNAL);
ASSERT_EQ(EPERM, pthread_kill(no_sandbox_thread, 0));
ASSERT_EQ(1, write(thread_pipe[1], ".", 1));
ASSERT_EQ(0, pthread_create(&scoped_thread, NULL, thread_func, NULL));
ASSERT_EQ(0, pthread_kill(scoped_thread, 0));
ASSERT_EQ(1, write(thread_pipe[1], ".", 1));
EXPECT_EQ(0, pthread_join(no_sandbox_thread, (void **)&ret));
EXPECT_EQ(THREAD_SUCCESS, ret);
EXPECT_EQ(0, pthread_join(scoped_thread, (void **)&ret));
EXPECT_EQ(THREAD_SUCCESS, ret);
EXPECT_EQ(0, close(thread_pipe[0]));
EXPECT_EQ(0, close(thread_pipe[1]));
}
TEST_HARNESS_MAIN