glibc: Fix CVE-2021-38604

Source: https://sourceware.org/git/glibc.git
Tracking -- https://sourceware.org/bugzilla/show_bug.cgi?id=28213

Backported upstream commits b805aebd42364fe696e417808a700fdb9800c9e8 and 4cc79c217744743077bf7a0ec5e0a4318f1e6641
to glibc-2.34 source.

Upstream-Status: Backport [https://sourceware.org/git/?p=glibc.git;a=commit;h=b805aebd42364fe696e417808a700fdb9800c9e8]
Upstream-Status: Backport [https://sourceware.org/git/?p=glibc.git;a=commit;h=4cc79c217744743077bf7a0ec5e0a4318f1e6641]

(From OE-Core rev: 014c6b0a1188d5dfb32790246491973ea91017d8)

Signed-off-by: Vinay Kumar <vinay.m.engg@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

2 files changed, 193 insertions, 0 deletions

diff --git a/meta/recipes-core/glibc/glibc/0001-CVE-2021-38604.patch b/meta/recipes-core/glibc/glibc/0001-CVE-2021-38604.patch
new file mode 100644
index 0000000000..1e94049004
--- /dev/null
+++ b/meta/recipes-core/glibc/glibc/0001-CVE-2021-38604.patch
@@ -0,0 +1,43 @@
+From b805aebd42364fe696e417808a700fdb9800c9e8 Mon Sep 17 00:00:00 2001
+From: Nikita Popov <npv1310@gmail.com>
+Date: Mon, 9 Aug 2021 20:17:34 +0530
+Subject: [PATCH] librt: fix NULL pointer dereference (bug 28213)
+
+Helper thread frees copied attribute on NOTIFY_REMOVED message
+received from the OS kernel.  Unfortunately, it fails to check whether
+copied attribute actually exists (data.attr != NULL).  This worked
+earlier because free() checks passed pointer before actually
+attempting to release corresponding memory.  But
+__pthread_attr_destroy assumes pointer is not NULL.
+
+So passing NULL pointer to __pthread_attr_destroy will result in
+segmentation fault.  This scenario is possible if
+notification->sigev_notify_attributes == NULL (which means default
+thread attributes should be used).
+
+Upstream-Status: Backport [https://sourceware.org/git/?p=glibc.git;a=commit;h=b805aebd42364fe696e417808a700fdb9800c9e8]
+CVE: CVE-2021-38604
+
+Signed-off-by: Nikita Popov <npv1310@gmail.com>
+Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
+Signed-off-by: Vinay Kumar <vinay.m.engg@gmail.com>
+---
+ sysdeps/unix/sysv/linux/mq_notify.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/sysdeps/unix/sysv/linux/mq_notify.c b/sysdeps/unix/sysv/linux/mq_notify.c
+index 9799dcdaa4..eccae2e4c6 100644
+--- a/sysdeps/unix/sysv/linux/mq_notify.c
++++ b/sysdeps/unix/sysv/linux/mq_notify.c
+@@ -131,7 +131,7 @@ helper_thread (void *arg)
+               to wait until it is done with it.  */
+            (void) __pthread_barrier_wait (&notify_barrier);
+        }
+-      else if (data.raw[NOTIFY_COOKIE_LEN - 1] == NOTIFY_REMOVED)
++      else if (data.raw[NOTIFY_COOKIE_LEN - 1] == NOTIFY_REMOVED && data.attr != NULL)
+        {
+          /* The only state we keep is the copy of the thread attributes.  */
+          __pthread_attr_destroy (data.attr);
+-- 
+2.31.1
+
diff --git a/meta/recipes-core/glibc/glibc/0002-CVE-2021-38604.patch b/meta/recipes-core/glibc/glibc/0002-CVE-2021-38604.patch
new file mode 100644
index 0000000000..9f71fecddb
--- /dev/null
+++ b/meta/recipes-core/glibc/glibc/0002-CVE-2021-38604.patch
@@ -0,0 +1,150 @@
+From 4cc79c217744743077bf7a0ec5e0a4318f1e6641 Mon Sep 17 00:00:00 2001
+From: Nikita Popov <npv1310@gmail.com>
+Date: Thu, 12 Aug 2021 16:09:50 +0530
+Subject: [PATCH] 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.
+
+Upstream-Status: Backport [https://sourceware.org/git/?p=glibc.git;a=commit;h=4cc79c217744743077bf7a0ec5e0a4318f1e6641]
+CVE: CVE-2021-38604
+
+Signed-off-by: Nikita Popov <npv1310@gmail.com>
+Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
+Signed-off-by: Vinay Kumar <vinay.m.engg@gmail.com>
+---
+ rt/Makefile      |   1 +
+ rt/tst-bz28213.c | 101 +++++++++++++++++++++++++++++++++++++++++++++++
+ 2 files changed, 102 insertions(+)
+ create mode 100644 rt/tst-bz28213.c
+
+diff --git a/rt/Makefile b/rt/Makefile
+index 113cea03a5..910e775995 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 0000000000..0c096b5a0a
+--- /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>
+-- 
+2.31.1
+