diff options
Diffstat (limited to 'tools/testing/selftests/seccomp/seccomp_bpf.c')
| -rw-r--r-- | tools/testing/selftests/seccomp/seccomp_bpf.c | 228 |
1 files changed, 228 insertions, 0 deletions
diff --git a/tools/testing/selftests/seccomp/seccomp_bpf.c b/tools/testing/selftests/seccomp/seccomp_bpf.c index e282f521f8d7..29c973f606b2 100644 --- a/tools/testing/selftests/seccomp/seccomp_bpf.c +++ b/tools/testing/selftests/seccomp/seccomp_bpf.c @@ -60,6 +60,8 @@ #define SKIP(s, ...) XFAIL(s, ##__VA_ARGS__) #endif +#define MIN(X, Y) ((X) < (Y) ? (X) : (Y)) + #ifndef PR_SET_PTRACER # define PR_SET_PTRACER 0x59616d61 #endif @@ -269,6 +271,10 @@ struct seccomp_notif_addfd_big { #define SECCOMP_FILTER_FLAG_TSYNC_ESRCH (1UL << 4) #endif +#ifndef SECCOMP_FILTER_FLAG_WAIT_KILLABLE_RECV +#define SECCOMP_FILTER_FLAG_WAIT_KILLABLE_RECV (1UL << 5) +#endif + #ifndef seccomp int seccomp(unsigned int op, unsigned int flags, void *args) { @@ -4428,6 +4434,228 @@ restart_wait: } } +/* get_proc_syscall - Get the syscall in progress for a given pid + * + * Returns the current syscall number for a given process + * Returns -1 if not in syscall (running or blocked) + */ +static long get_proc_syscall(struct __test_metadata *_metadata, int pid) +{ + char proc_path[100] = {0}; + long ret = -1; + ssize_t nread; + char *line; + + snprintf(proc_path, sizeof(proc_path), "/proc/%d/syscall", pid); + nread = get_nth(_metadata, proc_path, 1, &line); + ASSERT_GT(nread, 0); + + if (!strncmp("running", line, MIN(7, nread))) + ret = strtol(line, NULL, 16); + + free(line); + return ret; +} + +/* Ensure non-fatal signals prior to receive are unmodified */ +TEST(user_notification_wait_killable_pre_notification) +{ + struct sigaction new_action = { + .sa_handler = signal_handler, + }; + int listener, status, sk_pair[2]; + pid_t pid; + long ret; + char c; + /* 100 ms */ + struct timespec delay = { .tv_nsec = 100000000 }; + + ASSERT_EQ(sigemptyset(&new_action.sa_mask), 0); + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret) + { + TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); + } + + ASSERT_EQ(socketpair(PF_LOCAL, SOCK_SEQPACKET, 0, sk_pair), 0); + + listener = user_notif_syscall( + __NR_getppid, SECCOMP_FILTER_FLAG_NEW_LISTENER | + SECCOMP_FILTER_FLAG_WAIT_KILLABLE_RECV); + ASSERT_GE(listener, 0); + + /* + * Check that we can kill the process with SIGUSR1 prior to receiving + * the notification. SIGUSR1 is wired up to a custom signal handler, + * and make sure it gets called. + */ + pid = fork(); + ASSERT_GE(pid, 0); + + if (pid == 0) { + close(sk_pair[0]); + handled = sk_pair[1]; + + /* Setup the non-fatal sigaction without SA_RESTART */ + if (sigaction(SIGUSR1, &new_action, NULL)) { + perror("sigaction"); + exit(1); + } + + ret = syscall(__NR_getppid); + /* Make sure we got a return from a signal interruption */ + exit(ret != -1 || errno != EINTR); + } + + /* + * Make sure we've gotten to the seccomp user notification wait + * from getppid prior to sending any signals + */ + while (get_proc_syscall(_metadata, pid) != __NR_getppid && + get_proc_stat(_metadata, pid) != 'S') + nanosleep(&delay, NULL); + + /* Send non-fatal kill signal */ + EXPECT_EQ(kill(pid, SIGUSR1), 0); + + /* wait for process to exit (exit checks for EINTR) */ + EXPECT_EQ(waitpid(pid, &status, 0), pid); + EXPECT_EQ(true, WIFEXITED(status)); + EXPECT_EQ(0, WEXITSTATUS(status)); + + EXPECT_EQ(read(sk_pair[0], &c, 1), 1); +} + +/* Ensure non-fatal signals after receive are blocked */ +TEST(user_notification_wait_killable) +{ + struct sigaction new_action = { + .sa_handler = signal_handler, + }; + struct seccomp_notif_resp resp = {}; + struct seccomp_notif req = {}; + int listener, status, sk_pair[2]; + pid_t pid; + long ret; + char c; + /* 100 ms */ + struct timespec delay = { .tv_nsec = 100000000 }; + + ASSERT_EQ(sigemptyset(&new_action.sa_mask), 0); + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret) + { + TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); + } + + ASSERT_EQ(socketpair(PF_LOCAL, SOCK_SEQPACKET, 0, sk_pair), 0); + + listener = user_notif_syscall( + __NR_getppid, SECCOMP_FILTER_FLAG_NEW_LISTENER | + SECCOMP_FILTER_FLAG_WAIT_KILLABLE_RECV); + ASSERT_GE(listener, 0); + + pid = fork(); + ASSERT_GE(pid, 0); + + if (pid == 0) { + close(sk_pair[0]); + handled = sk_pair[1]; + + /* Setup the sigaction without SA_RESTART */ + if (sigaction(SIGUSR1, &new_action, NULL)) { + perror("sigaction"); + exit(1); + } + + /* Make sure that the syscall is completed (no EINTR) */ + ret = syscall(__NR_getppid); + exit(ret != USER_NOTIF_MAGIC); + } + + /* + * Get the notification, to make move the notifying process into a + * non-preemptible (TASK_KILLABLE) state. + */ + EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0); + /* Send non-fatal kill signal */ + EXPECT_EQ(kill(pid, SIGUSR1), 0); + + /* + * Make sure the task enters moves to TASK_KILLABLE by waiting for + * D (Disk Sleep) state after receiving non-fatal signal. + */ + while (get_proc_stat(_metadata, pid) != 'D') + nanosleep(&delay, NULL); + + resp.id = req.id; + resp.val = USER_NOTIF_MAGIC; + /* Make sure the notification is found and able to be replied to */ + EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0); + + /* + * Make sure that the signal handler does get called once we're back in + * userspace. + */ + EXPECT_EQ(read(sk_pair[0], &c, 1), 1); + /* wait for process to exit (exit checks for USER_NOTIF_MAGIC) */ + EXPECT_EQ(waitpid(pid, &status, 0), pid); + EXPECT_EQ(true, WIFEXITED(status)); + EXPECT_EQ(0, WEXITSTATUS(status)); +} + +/* Ensure fatal signals after receive are not blocked */ +TEST(user_notification_wait_killable_fatal) +{ + struct seccomp_notif req = {}; + int listener, status; + pid_t pid; + long ret; + /* 100 ms */ + struct timespec delay = { .tv_nsec = 100000000 }; + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret) + { + TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); + } + + listener = user_notif_syscall( + __NR_getppid, SECCOMP_FILTER_FLAG_NEW_LISTENER | + SECCOMP_FILTER_FLAG_WAIT_KILLABLE_RECV); + ASSERT_GE(listener, 0); + + pid = fork(); + ASSERT_GE(pid, 0); + + if (pid == 0) { + /* This should never complete as it should get a SIGTERM */ + syscall(__NR_getppid); + exit(1); + } + + while (get_proc_stat(_metadata, pid) != 'S') + nanosleep(&delay, NULL); + + /* + * Get the notification, to make move the notifying process into a + * non-preemptible (TASK_KILLABLE) state. + */ + EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0); + /* Kill the process with a fatal signal */ + EXPECT_EQ(kill(pid, SIGTERM), 0); + + /* + * Wait for the process to exit, and make sure the process terminated + * due to the SIGTERM signal. + */ + EXPECT_EQ(waitpid(pid, &status, 0), pid); + EXPECT_EQ(true, WIFSIGNALED(status)); + EXPECT_EQ(SIGTERM, WTERMSIG(status)); +} + /* * TODO: * - expand NNP testing |