Add fix for CVE-2020-24977 (RHBZ#1877788).

libxml2-2.9.10-CVE-2020-24977.patch

@@ -0,0 +1,41 @@
+From 8e7c20a1af8776677d7890f30b7a180567701a49 Mon Sep 17 00:00:00 2001
+From: Nick Wellnhofer <wellnhofer@aevum.de>
+Date: Mon, 3 Aug 2020 17:30:41 +0200
+Subject: [PATCH] Fix integer overflow when comparing schema dates
+
+Found by OSS-Fuzz.
+---
+ xmlschemastypes.c | 10 ++++++++++
+ 1 file changed, 10 insertions(+)
+
+diff --git a/xmlschemastypes.c b/xmlschemastypes.c
+index 4249d700..d6b9f924 100644
+--- a/xmlschemastypes.c
++++ b/xmlschemastypes.c
+@@ -3691,6 +3691,8 @@ xmlSchemaCompareDurations(xmlSchemaValPtr x, xmlSchemaValPtr y)
+ 	minday = 0;
+ 	maxday = 0;
+     } else {
++        if (myear > LONG_MAX / 366)
++            return -2;
+         /* FIXME: This doesn't take leap year exceptions every 100/400 years
+            into account. */
+ 	maxday = 365 * myear + (myear + 3) / 4;
+@@ -4079,6 +4081,14 @@ xmlSchemaCompareDates (xmlSchemaValPtr x, xmlSchemaValPtr y)
+     if ((x == NULL) || (y == NULL))
+         return -2;
+ 
++    if ((x->value.date.year > LONG_MAX / 366) ||
++        (x->value.date.year < LONG_MIN / 366) ||
++        (y->value.date.year > LONG_MAX / 366) ||
++        (y->value.date.year < LONG_MIN / 366)) {
++        /* Possible overflow when converting to days. */
++        return -2;
++    }
++
+     if (x->value.date.tz_flag) {
+ 
+         if (!y->value.date.tz_flag) {
+-- 
+2.28.0.rc2
+

libxml2.spec

@@ -1,6 +1,6 @@
 Name:           libxml2
 Version:        2.9.10
-Release:        6%{?dist}
+Release:        7%{?dist}
 Summary:        Library providing XML and HTML support
 
 License:        MIT
@@ -17,6 +17,8 @@ Patch3:         libxml2-2.9.10-CVE-2019-20388.patch
 Patch4:         libxml2-2.9.10-CVE-2020-7595.patch
 # https://gitlab.gnome.org/GNOME/libxml2/merge_requests/71
 Patch5:         libxml2-2.9.10-parenthesize-type-checks.patch
+# https://bugzilla.redhat.com/show_bug.cgi?id=1877788
+Patch6:         libxml2-2.9.10-CVE-2020-24977.patch
 
 BuildRequires:  gcc
 BuildRequires:  make
@@ -145,6 +147,9 @@ gzip -9 -c doc/libxml2-api.xml > doc/libxml2-api.xml.gz
 %{python3_sitearch}/libxml2mod.so
 
 %changelog
+* Fri Sep 11 2020 Richard W.M. Jones <rjones@redhat.com> - 2.9.10-7
+- Add fix for CVE-2020-24977 (RHBZ#1877788).
+
 * Tue Jul 28 2020 Fedora Release Engineering <releng@fedoraproject.org> - 2.9.10-6
 - Rebuilt for https://fedoraproject.org/wiki/Fedora_33_Mass_Rebuild