| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-Id: <20210430204939.5152-4-sargun@sargun.me>
Date: Fri, 30 Apr 2021 13:49:37 -0700
From: Sargun Dhillon <sargun@...gun.me>
To: Kees Cook <keescook@...omium.org>,
LKML <linux-kernel@...r.kernel.org>,
Linux Containers <containers@...ts.linux-foundation.org>
Cc: Sargun Dhillon <sargun@...gun.me>,
Mauricio Vásquez Bernal <mauricio@...volk.io>,
Rodrigo Campos <rodrigo@...volk.io>,
Tycho Andersen <tycho@...ho.pizza>,
Giuseppe Scrivano <gscrivan@...hat.com>,
Christian Brauner <christian.brauner@...ntu.com>,
Andy Lutomirski <luto@...nel.org>
Subject: [PATCH v2 3/5] selftests/seccomp: Add test for wait killable notifier
This adds a test for the positive case of the wait killable notifier,
in testing that when the feature is activated the process acts as
expected -- in not terminating on a non-fatal signal, and instead
queueing it up. There is already a test case for normal handlers
and preemption.
Signed-off-by: Sargun Dhillon <sargun@...gun.me>
---
tools/testing/selftests/seccomp/seccomp_bpf.c | 152 ++++++++++++++++++
1 file changed, 152 insertions(+)
diff --git a/tools/testing/selftests/seccomp/seccomp_bpf.c b/tools/testing/selftests/seccomp/seccomp_bpf.c
index 98c3b647f54d..9a72ba8bb4f7 100644
--- a/tools/testing/selftests/seccomp/seccomp_bpf.c
+++ b/tools/testing/selftests/seccomp/seccomp_bpf.c
@@ -235,6 +235,11 @@ struct seccomp_notif_addfd {
};
#endif
+#ifndef SECCOMP_IOCTL_NOTIF_SET_WAIT_KILLABLE
+/* Set flag to prevent non-fatal signal preemption */
+#define SECCOMP_IOCTL_NOTIF_SET_WAIT_KILLABLE SECCOMP_IOW(4, __u64)
+#endif
+
struct seccomp_notif_addfd_small {
__u64 id;
char weird[4];
@@ -4135,6 +4140,153 @@ TEST(user_notification_addfd_rlimit)
close(memfd);
}
+/* Parses /proc/$PID/status, and stores the state and shdpnd */
+static void parse_status(pid_t pid, char *state, long long *shdpnd)
+{
+ char *line = NULL;
+ char proc_path[100] = {0};
+ size_t len = 0;
+ FILE *f;
+
+ snprintf(proc_path, sizeof(proc_path), "/proc/%d/status", pid);
+ f = fopen(proc_path, "r");
+ if (f == NULL)
+ ksft_exit_fail_msg("%s - Could not open %s\n",
+ strerror(errno), proc_path);
+
+ while (getline(&line, &len, f) != -1) {
+ if (strstr(line, "State")) {
+ if (sscanf(line, "State:\t%c", state) != 1)
+ ksft_exit_fail_msg("Couldn't parse state %s\n",
+ line);
+ }
+
+ if (strstr(line, "ShdPnd")) {
+ if (sscanf(line, "ShdPnd:\t%llx", shdpnd) != 1)
+ ksft_exit_fail_msg("Couldn't parse shdpnd %s\n",
+ line);
+ }
+ }
+
+ free(line);
+ fclose(f);
+}
+
+TEST(user_notification_signal_wait_killable)
+{
+ struct seccomp_notif_resp resp = {};
+ struct seccomp_notif req = {};
+ int status, listener;
+ long long sigpnd;
+ char state;
+ pid_t pid;
+ long ret;
+
+ 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_gettid,
+ SECCOMP_FILTER_FLAG_NEW_LISTENER);
+ ASSERT_GE(listener, 0);
+
+ pid = fork();
+ ASSERT_GE(pid, 0);
+
+ if (pid == 0) {
+ sigset_t mask;
+
+ sigemptyset(&mask);
+ sigaddset(&mask, SIGUSR1);
+
+ EXPECT_EQ(sigprocmask(SIG_BLOCK, &mask, NULL), 0);
+
+ /* Check once for wait_killable */
+ if (syscall(__NR_gettid) != 42)
+ exit(1);
+
+ EXPECT_EQ(SIGUSR1, sigwaitinfo(&mask, NULL));
+
+ exit(42);
+ }
+
+ ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
+
+ /* Wait interruptible should be in sleep */
+ parse_status(pid, &state, &sigpnd);
+ ASSERT_EQ(state, 'S');
+
+ ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SET_WAIT_KILLABLE, &req.id), 0);
+ EXPECT_EQ(kill(pid, SIGUSR1), 0);
+
+ /* Check for transition to "disk sleep" -- async (or timeout) */
+ do {
+ usleep(100);
+ parse_status(pid, &state, &sigpnd);
+ } while (state != 'D');
+ EXPECT_EQ(sigpnd, (1 << (SIGUSR1 - 1)));
+
+ /* Make sure idempotency is handled correctly */
+ EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SET_WAIT_KILLABLE, &req.id), -1);
+ EXPECT_EQ(errno, EALREADY);
+
+ resp.id = req.id;
+ resp.error = 0;
+ resp.val = 42;
+
+ EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
+
+ EXPECT_EQ(waitpid(pid, &status, 0), pid);
+ EXPECT_EQ(true, WIFEXITED(status));
+ EXPECT_EQ(42, WEXITSTATUS(status));
+}
+
+
+TEST(user_notification_signal_wait_killable_kill)
+{
+ struct seccomp_notif req = {};
+ int status, listener;
+ long long sigpnd;
+ char state;
+ pid_t pid;
+ long ret;
+
+ 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_gettid,
+ SECCOMP_FILTER_FLAG_NEW_LISTENER);
+ ASSERT_GE(listener, 0);
+
+ pid = fork();
+ ASSERT_GE(pid, 0);
+
+ if (pid == 0) {
+ syscall(__NR_gettid);
+ exit(1);
+ }
+
+ ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
+ ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SET_WAIT_KILLABLE, &req.id), 0);
+ do {
+ usleep(100);
+ parse_status(pid, &state, &sigpnd);
+ } while (state != 'D');
+
+ EXPECT_EQ(kill(pid, SIGKILL), 0);
+
+ EXPECT_EQ(waitpid(pid, &status, 0), pid);
+ EXPECT_EQ(true, WIFSIGNALED(status));
+ EXPECT_EQ(9, WTERMSIG(status));
+
+ /* Make sure the notification is invalidated properly */
+ EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ID_VALID, &req.id), -1);
+}
+
+
/*
* TODO:
* - expand NNP testing
--
2.25.1
Powered by blists - more mailing lists