[LTP] [PATCH v2] mq_notify03.c: New test CVE-2021-38604

[Wei Gao]

This test is come from glibc test mq_notify.c.
Implements following logic:
1) Create POSIX message queue.
   Register a notification with mq_notify (using NULL attributes).
   Then immediately unregister the notification with mq_notify.
   Helper thread in a vulnerable version of glibc
   should cause NULL pointer dereference after these steps.
2) Once again, register the same notification.
   Try to send a dummy message.
   Test is considered successfulif the dummy message
   is successfully received by the callback function.

Signed-off-by: Wei Gao <wegao@suse.com>
---
 runtest/cve                                   |  1 +
 runtest/syscalls                              |  1 +
 .../kernel/syscalls/mq_notify/.gitignore      |  1 +
 .../kernel/syscalls/mq_notify/mq_notify03.c   | 99 +++++++++++++++++++
 4 files changed, 102 insertions(+)
 create mode 100644 testcases/kernel/syscalls/mq_notify/mq_notify03.c

diff --git a/runtest/cve b/runtest/cve
index 1ba63c2a7..07bcac0b0 100644
--- a/runtest/cve
+++ b/runtest/cve
@@ -74,6 +74,7 @@ cve-2021-26708 vsock01
 cve-2021-22600 setsockopt09
 cve-2022-0847 dirtypipe
 cve-2022-2590 dirtyc0w_shmem
+cve-2021-38604 mq_notify03
 # Tests below may cause kernel memory leak
 cve-2020-25704 perf_event_open03
 cve-2022-4378 cve-2022-4378
diff --git a/runtest/syscalls b/runtest/syscalls
index 81c30402b..536140a3e 100644
--- a/runtest/syscalls
+++ b/runtest/syscalls
@@ -832,6 +832,7 @@ pkey01 pkey01
 
 mq_notify01 mq_notify01
 mq_notify02 mq_notify02
+mq_notify03 mq_notify03
 mq_open01 mq_open01
 mq_timedreceive01 mq_timedreceive01
 mq_timedsend01 mq_timedsend01
diff --git a/testcases/kernel/syscalls/mq_notify/.gitignore b/testcases/kernel/syscalls/mq_notify/.gitignore
index cca05a7fa..3f9403c05 100644
--- a/testcases/kernel/syscalls/mq_notify/.gitignore
+++ b/testcases/kernel/syscalls/mq_notify/.gitignore
@@ -1,2 +1,3 @@
 /mq_notify01
 /mq_notify02
+/mq_notify03
diff --git a/testcases/kernel/syscalls/mq_notify/mq_notify03.c b/testcases/kernel/syscalls/mq_notify/mq_notify03.c
new file mode 100644
index 000000000..5c322ef0e
--- /dev/null
+++ b/testcases/kernel/syscalls/mq_notify/mq_notify03.c
@@ -0,0 +1,99 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) The GNU Toolchain Authors.
+ * Copyright (c) 2023 Wei Gao <wegao@suse.com>
+ *
+ */
+
+/*\
+ * [Description]
+ *
+ * Test for NULL pointer dereference in mq_notify(CVE-2021-38604)
+ *
+ * References links:
+ * - https://sourceware.org/bugzilla/show_bug.cgi?id=28213
+ */
+
+#include <errno.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <mqueue.h>
+#include <signal.h>
+#include <stdlib.h>
+#include <string.h>
+#include "tst_test.h"
+#include "tst_safe_posix_ipc.h"
+
+static mqd_t m = -1;
+static const char msg[] = "hello";
+
+static void try_null_dereference_cb(union sigval sv)
+{
+	char buf[sizeof(msg)];
+
+	(void)sv;
+
+	TST_EXP_VAL((size_t) mq_receive(m, buf, sizeof(buf), NULL)
+				, sizeof(buf));
+	TST_EXP_PASS(memcmp(buf, msg, sizeof(buf)));
+
+	exit(0);
+}
+
+static void try_null_dereference(void)
+{
+	struct sigevent sev;
+
+	memset(&sev, '\0', sizeof(sev));
+	sev.sigev_notify = SIGEV_THREAD;
+	sev.sigev_notify_function = try_null_dereference_cb;
+
+	/* Step 1: Register & unregister notifier.
+	 * Helper thread should receive NOTIFY_REMOVED notification.
+	 * In a vulnerable version of glibc, NULL pointer dereference follows.
+	 */
+	TST_EXP_PASS(mq_notify(m, &sev));
+	TST_EXP_PASS(mq_notify(m, NULL));
+
+	/* Step 2: Once again, register notification.
+	 * Try to send one message.
+	 * Test is considered successful, if the callback does exit (0).
+	 */
+	TST_EXP_PASS(mq_notify(m, &sev));
+	TST_EXP_PASS(mq_send(m, msg, sizeof(msg), 1));
+
+	/* Wait... */
+	pause();
+}
+
+static void do_test(void)
+{
+	static const char m_name[] = "/ltp_mq_notify03";
+	struct mq_attr m_attr;
+
+	memset(&m_attr, '\0', sizeof(m_attr));
+	m_attr.mq_maxmsg = 1;
+	m_attr.mq_msgsize = sizeof(msg);
+
+	m = SAFE_MQ_OPEN(m_name,
+			O_RDWR | O_CREAT | O_EXCL,
+			0600,
+			&m_attr);
+
+	TST_EXP_PASS(mq_unlink(m_name));
+
+	try_null_dereference();
+}
+
+
+static struct tst_test test = {
+	.test_all = do_test,
+	.tags = (const struct tst_tag[]) {
+		{"glibc-git", "b805aebd42"},
+		{"CVE", "2021-38604"},
+		{}
+	},
+	.needs_root = 1,
+};
-- 
2.35.3