--- /dev/null
+From 709674ec86c3c6da4f0995897f6b0205c16d049d Mon Sep 17 00:00:00 2001
+From: Andreas Schwab <schwab@linux-m68k.org>
+Date: Thu, 27 May 2021 12:49:47 +0200
+Subject: [PATCH] Use __pthread_attr_copy in mq_notify (bug 27896)
+
+Make a deep copy of the pthread attribute object to remove a potential
+use-after-free issue.
+
+Upstream-Status: Backport
+[https://sourceware.org/git/?p=glibc.git;a=commit;h=42d359350510506b87101cf77202fefcbfc790cb]
+
+CVE:
+CVE-2021-33574
+
+Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
+Signed-off-by: Khairul Rohaizzat Jamaluddin <khairul.rohaizzat.jamaluddin@intel.com>
+---
+ NEWS | 4 ++++
+ sysdeps/unix/sysv/linux/mq_notify.c | 15 ++++++++++-----
+ 2 files changed, 14 insertions(+), 5 deletions(-)
+
+diff --git a/NEWS b/NEWS
+index 71f5d20324..017d656433 100644
+--- a/NEWS
++++ b/NEWS
+@@ -118,6 +118,10 @@ Security related changes:
+ CVE-2019-25013: A buffer overflow has been fixed in the iconv function when
+ invoked with EUC-KR input containing invalid multibyte input sequences.
+
++ CVE-2021-33574: The mq_notify function has a potential use-after-free
++ issue when using a notification type of SIGEV_THREAD and a thread
++ attribute with a non-default affinity mask.
++
+ The following bugs are resolved with this release:
+
+ [10635] libc: realpath portability patches
+diff --git a/sysdeps/unix/sysv/linux/mq_notify.c b/sysdeps/unix/sysv/linux/mq_notify.c
+index cc575a0cdd..f7ddfe5a6c 100644
+--- a/sysdeps/unix/sysv/linux/mq_notify.c
++++ b/sysdeps/unix/sysv/linux/mq_notify.c
+@@ -133,8 +133,11 @@ helper_thread (void *arg)
+ (void) __pthread_barrier_wait (¬ify_barrier);
+ }
+ else if (data.raw[NOTIFY_COOKIE_LEN - 1] == NOTIFY_REMOVED)
+- /* The only state we keep is the copy of the thread attributes. */
+- free (data.attr);
++ {
++ /* The only state we keep is the copy of the thread attributes. */
++ pthread_attr_destroy (data.attr);
++ free (data.attr);
++ }
+ }
+ return NULL;
+ }
+@@ -255,8 +258,7 @@ mq_notify (mqd_t mqdes, const struct sigevent *notification)
+ if (data.attr == NULL)
+ return -1;
+
+- memcpy (data.attr, notification->sigev_notify_attributes,
+- sizeof (pthread_attr_t));
++ __pthread_attr_copy (data.attr, notification->sigev_notify_attributes);
+ }
+
+ /* Construct the new request. */
+@@ -270,7 +272,10 @@ mq_notify (mqd_t mqdes, const struct sigevent *notification)
+
+ /* If it failed, free the allocated memory. */
+ if (__glibc_unlikely (retval != 0))
+- free (data.attr);
++ {
++ pthread_attr_destroy (data.attr);
++ free (data.attr);
++ }
+
+ return retval;
+ }
--- /dev/null
+From 217b6dc298156bdb0d6aea9ea93e7e394a5ff091 Mon Sep 17 00:00:00 2001
+From: Florian Weimer <fweimer@redhat.com>
+Date: Tue, 1 Jun 2021 17:51:41 +0200
+Subject: [PATCH] Fix use of __pthread_attr_copy in mq_notify (bug 27896)
+
+__pthread_attr_copy can fail and does not initialize the attribute
+structure in that case.
+
+If __pthread_attr_copy is never called and there is no allocated
+attribute, pthread_attr_destroy should not be called, otherwise
+there is a null pointer dereference in rt/tst-mqueue6.
+
+Fixes commit 42d359350510506b87101cf77202fefcbfc790cb
+("Use __pthread_attr_copy in mq_notify (bug 27896)").
+
+Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
+
+Upstream-Status: Backport
+[https://sourceware.org/git/?p=glibc.git;a=commit;h=217b6dc298156bdb0d6aea9ea93e7e394a5ff091]
+
+CVE:
+CVE-2021-33574
+
+Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
+Signed-off-by: Khairul Rohaizzat Jamaluddin <khairul.rohaizzat.jamaluddin@intel.com>
+---
+ sysdeps/unix/sysv/linux/mq_notify.c | 11 +++++++++--
+ 1 file changed, 9 insertions(+), 2 deletions(-)
+
+diff --git a/sysdeps/unix/sysv/linux/mq_notify.c b/sysdeps/unix/sysv/linux/mq_notify.c
+index f7ddfe5a6c..6f46d29d1d 100644
+--- a/sysdeps/unix/sysv/linux/mq_notify.c
++++ b/sysdeps/unix/sysv/linux/mq_notify.c
+@@ -258,7 +258,14 @@ mq_notify (mqd_t mqdes, const struct sigevent *notification)
+ if (data.attr == NULL)
+ return -1;
+
+- __pthread_attr_copy (data.attr, notification->sigev_notify_attributes);
++ int ret = __pthread_attr_copy (data.attr,
++ notification->sigev_notify_attributes);
++ if (ret != 0)
++ {
++ free (data.attr);
++ __set_errno (ret);
++ return -1;
++ }
+ }
+
+ /* Construct the new request. */
+@@ -271,7 +278,7 @@ mq_notify (mqd_t mqdes, const struct sigevent *notification)
+ int retval = INLINE_SYSCALL (mq_notify, 2, mqdes, &se);
+
+ /* If it failed, free the allocated memory. */
+- if (__glibc_unlikely (retval != 0))
++ if (retval != 0 && data.attr != NULL)
+ {
+ pthread_attr_destroy (data.attr);
+ free (data.attr);
+--
+2.27.0
+
