[Dunfell][PATCH 2/7] glibc: Security fix for CVE-2021-38604

["Armin Kuster" <akuster808@gmail.com>]

From: Armin Kuster <akuster@mvista.com>

Source: glibc.org
MR: 112635
Type: Security Fix
Disposition: Backport from https://sourceware.org/git/?p=glibc.git;a=commit;h=b805aebd42364fe696e417808a700fdb9800c9e8
ChangeID: 53b105da48e604f6763bb04b7114f41bfb620d2f
Description:

Signed-off-by: Armin Kuster <akuster@mvista.com>
---
 .../glibc/glibc/CVE-2021-38604.patch          | 41 +++++++++++++++++++
 meta/recipes-core/glibc/glibc_2.31.bb         |  1 +
 2 files changed, 42 insertions(+)
 create mode 100644 meta/recipes-core/glibc/glibc/CVE-2021-38604.patch

diff --git a/meta/recipes-core/glibc/glibc/CVE-2021-38604.patch b/meta/recipes-core/glibc/glibc/CVE-2021-38604.patch
new file mode 100644
index 0000000000..36fd4a61b2
--- /dev/null
+++ b/meta/recipes-core/glibc/glibc/CVE-2021-38604.patch
@@ -0,0 +1,41 @@
+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).
+
+Signed-off-by: Nikita Popov <npv1310@gmail.com>
+Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
+
+Upstream-Status: Backport
+CVE: CVE-2021-38604
+Signed-off-by: Armin Kuser <akuster@mvista.com>
+
+---
+ sysdeps/unix/sysv/linux/mq_notify.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+Index: git/sysdeps/unix/sysv/linux/mq_notify.c
+===================================================================
+--- git.orig/sysdeps/unix/sysv/linux/mq_notify.c
++++ git/sysdeps/unix/sysv/linux/mq_notify.c
+@@ -134,7 +134,7 @@ 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);
diff --git a/meta/recipes-core/glibc/glibc_2.31.bb b/meta/recipes-core/glibc/glibc_2.31.bb
index 2e950dfeda..3a3586f1b9 100644
--- a/meta/recipes-core/glibc/glibc_2.31.bb
+++ b/meta/recipes-core/glibc/glibc_2.31.bb
@@ -69,6 +69,7 @@ SRC_URI =  "${GLIBC_GIT_URI};branch=${SRCBRANCH};name=glibc \
            file://CVE-2020-29573.patch \
            file://CVE-2021-33574_1.patch \
            file://CVE-2021-33574_2.patch \
+           file://CVE-2021-38604.patch \
            "
 S = "${WORKDIR}/git"
 B = "${WORKDIR}/build-${TARGET_SYS}"
-- 
2.25.1