commit 7c987a5ccb31df80456d53a094e47f81310f549b

Author: Nikita Popov <npv1310@gmail.com>

Date:   Thu Aug 12 16:09:50 2021 +0530

    librt: add test (bug 28213)

    This test 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: Nikita Popov <npv1310@gmail.com>

    Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>

    (cherry picked from commit 4cc79c217744743077bf7a0ec5e0a4318f1e6641)

diff --git a/rt/Makefile b/rt/Makefile

index 113cea03a5b75613..910e7759956d7ae9 100644

--- a/rt/Makefile

+++ b/rt/Makefile

@@ -74,6 +74,7 @@ tests := tst-shm tst-timer tst-timer2 \

 	 tst-aio7 tst-aio8 tst-aio9 tst-aio10 \

 	 tst-mqueue1 tst-mqueue2 tst-mqueue3 tst-mqueue4 \

 	 tst-mqueue5 tst-mqueue6 tst-mqueue7 tst-mqueue8 tst-mqueue9 \

+	 tst-bz28213 \

 	 tst-timer3 tst-timer4 tst-timer5 \

 	 tst-cpuclock2 tst-cputimer1 tst-cputimer2 tst-cputimer3 \

 	 tst-shm-cancel \

diff --git a/rt/tst-bz28213.c b/rt/tst-bz28213.c

new file mode 100644

index 0000000000000000..0c096b5a0ad4170a

--- /dev/null

+++ b/rt/tst-bz28213.c

@@ -0,0 +1,101 @@

+/* Bug 28213: test for NULL pointer dereference in mq_notify.

+   Copyright (C) The GNU Toolchain Authors.

+   This file is part of the GNU C Library.

+

+   The GNU C Library is free software; you can redistribute it and/or

+   modify it under the terms of the GNU Lesser General Public

+   License as published by the Free Software Foundation; either

+   version 2.1 of the License, or (at your option) any later version.

+

+   The GNU C Library is distributed in the hope that it will be useful,

+   but WITHOUT ANY WARRANTY; without even the implied warranty of

+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

+   Lesser General Public License for more details.

+

+   You should have received a copy of the GNU Lesser General Public

+   License along with the GNU C Library; if not, see

+   <https://www.gnu.org/licenses/>.  */

+

+#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 <support/check.h>

+

+static mqd_t m = -1;

+static const char msg[] = "hello";

+

+static void

+check_bz28213_cb (union sigval sv)

+{

+  char buf[sizeof (msg)];

+

+  (void) sv;

+

+  TEST_VERIFY_EXIT ((size_t) mq_receive (m, buf, sizeof (buf), NULL)

+		    == sizeof (buf));

+  TEST_VERIFY_EXIT (memcmp (buf, msg, sizeof (buf)) == 0);

+

+  exit (0);

+}

+

+static void

+check_bz28213 (void)

+{

+  struct sigevent sev;

+

+  memset (&sev, '\0', sizeof (sev));

+  sev.sigev_notify = SIGEV_THREAD;

+  sev.sigev_notify_function = check_bz28213_cb;

+

+  /* Step 1: Register & unregister notifier.

+     Helper thread should receive NOTIFY_REMOVED notification.

+     In a vulnerable version of glibc, NULL pointer dereference follows. */

+  TEST_VERIFY_EXIT (mq_notify (m, &sev) == 0);

+  TEST_VERIFY_EXIT (mq_notify (m, NULL) == 0);

+

+  /* Step 2: Once again, register notification.

+     Try to send one message.

+     Test is considered successful, if the callback does exit (0). */

+  TEST_VERIFY_EXIT (mq_notify (m, &sev) == 0);

+  TEST_VERIFY_EXIT (mq_send (m, msg, sizeof (msg), 1) == 0);

+

+  /* Wait... */

+  pause ();

+}

+

+static int

+do_test (void)

+{

+  static const char m_name[] = "/bz28213_queue";

+  struct mq_attr m_attr;

+

+  memset (&m_attr, '\0', sizeof (m_attr));

+  m_attr.mq_maxmsg = 1;

+  m_attr.mq_msgsize = sizeof (msg);

+

+  m = mq_open (m_name,

+               O_RDWR | O_CREAT | O_EXCL,

+               0600,

+               &m_attr);

+

+  if (m < 0)

+    {

+      if (errno == ENOSYS)

+        FAIL_UNSUPPORTED ("POSIX message queues are not implemented\n");

+      FAIL_EXIT1 ("Failed to create POSIX message queue: %m\n");

+    }

+

+  TEST_VERIFY_EXIT (mq_unlink (m_name) == 0);

+

+  check_bz28213 ();

+

+  return 0;

+}

+

+#include <support/test-driver.c>