libtasn1: CVE-2017-10790

The _asn1_check_identifier function in GNU Libtasn1 through 4.12 causes
a NULL pointer dereference and crash when reading crafted input that
triggers assignment of a NULL value within an asn1_node structure. It
may lead to a remote denial of service attack.

References:
https://nvd.nist.gov/vuln/detail/CVE-2017-10790
http://git.savannah.gnu.org/gitweb/?p=libtasn1.git;a=commit;
h=d8d805e1f2e6799bb2dff4871a8598dc83088a39

(From OE-Core rev: 6176151625c971de031e14c97601ffd75a29772f)

Signed-off-by: Yue Tao <Yue.Tao@windriver.com>
Signed-off-by: Wenzong Fan <wenzong.fan@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

2 files changed, 64 insertions, 0 deletions

diff --git a/meta/recipes-support/gnutls/libtasn1/CVE-2017-10790.patch b/meta/recipes-support/gnutls/libtasn1/CVE-2017-10790.patch
new file mode 100644
index 0000000000..be843808a2
--- /dev/null
+++ b/meta/recipes-support/gnutls/libtasn1/CVE-2017-10790.patch
@@ -0,0 +1,63 @@
+From d8d805e1f2e6799bb2dff4871a8598dc83088a39 Mon Sep 17 00:00:00 2001
+From: Nikos Mavrogiannopoulos <nmav@redhat.com>
+Date: Thu, 22 Jun 2017 16:31:37 +0200
+Subject: [PATCH] _asn1_check_identifier: safer access to values read
+
+Signed-off-by: Nikos Mavrogiannopoulos <nmav@redhat.com>
+
+http://git.savannah.gnu.org/gitweb/?p=libtasn1.git;a=commit;h=d8d805e1f2e6799bb2dff4871a8598dc83088a39
+Upstream-Status: Backport
+
+CVE: CVE-2017-10790
+
+Signed-off-by: Yue Tao <Yue.Tao@windriver.com>
+Signed-off-by: Wenzong Fan <wenzong.fan@windriver.com>
+---
+ lib/parser_aux.c |   17 ++++++++++++-----
+ 1 file changed, 12 insertions(+), 5 deletions(-)
+
+diff --git a/lib/parser_aux.c b/lib/parser_aux.c
+index 976ab38..786ea64 100644
+--- a/lib/parser_aux.c
++++ b/lib/parser_aux.c
+@@ -955,7 +955,7 @@ _asn1_check_identifier (asn1_node node)
+          if (p2 == NULL)
+            {
+              if (p->value)
+-               _asn1_strcpy (_asn1_identifierMissing, p->value);
++               _asn1_str_cpy (_asn1_identifierMissing, sizeof(_asn1_identifierMissing), (char*)p->value);
+              else
+                _asn1_strcpy (_asn1_identifierMissing, "(null)");
+              return ASN1_IDENTIFIER_NOT_FOUND;
+@@ -968,9 +968,15 @@ _asn1_check_identifier (asn1_node node)
+          if (p2 && (type_field (p2->type) == ASN1_ETYPE_DEFAULT))
+            {
+              _asn1_str_cpy (name2, sizeof (name2), node->name);
+-             _asn1_str_cat (name2, sizeof (name2), ".");
+-             _asn1_str_cat (name2, sizeof (name2), (char *) p2->value);
+-             _asn1_strcpy (_asn1_identifierMissing, p2->value);
++             if (p2->value)
++               {
++                 _asn1_str_cat (name2, sizeof (name2), ".");
++                 _asn1_str_cat (name2, sizeof (name2), (char *) p2->value);
++                 _asn1_str_cpy (_asn1_identifierMissing, sizeof(_asn1_identifierMissing), (char*)p2->value);
++               }
++             else
++               _asn1_strcpy (_asn1_identifierMissing, "(null)");
++
+              p2 = asn1_find_node (node, name2);
+              if (!p2 || (type_field (p2->type) != ASN1_ETYPE_OBJECT_ID) ||
+                  !(p2->type & CONST_ASSIGN))
+@@ -990,7 +996,8 @@ _asn1_check_identifier (asn1_node node)
+                  _asn1_str_cpy (name2, sizeof (name2), node->name);
+                  _asn1_str_cat (name2, sizeof (name2), ".");
+                  _asn1_str_cat (name2, sizeof (name2), (char *) p2->value);
+-                 _asn1_strcpy (_asn1_identifierMissing, p2->value);
++                 _asn1_str_cpy (_asn1_identifierMissing, sizeof(_asn1_identifierMissing), (char*)p2->value);
++
+                  p2 = asn1_find_node (node, name2);
+                  if (!p2 || (type_field (p2->type) != ASN1_ETYPE_OBJECT_ID)
+                      || !(p2->type & CONST_ASSIGN))
+-- 
+1.7.9.5
+
diff --git a/meta/recipes-support/gnutls/libtasn1_4.12.bb b/meta/recipes-support/gnutls/libtasn1_4.12.bb
index cec1a9b156..7a7571ad3b 100644
--- a/meta/recipes-support/gnutls/libtasn1_4.12.bb
+++ b/meta/recipes-support/gnutls/libtasn1_4.12.bb
@@ -11,6 +11,7 @@ LIC_FILES_CHKSUM = "file://COPYING;md5=d32239bcb673463ab874e80d47fae504 \
 SRC_URI = "${GNU_MIRROR}/libtasn1/libtasn1-${PV}.tar.gz \
            file://dont-depend-on-help2man.patch \
            file://0001-stdint.m4-reintroduce-GNULIB_OVERRIDES_WINT_T-check.patch \
+           file://CVE-2017-10790.patch \
            "
 
 DEPENDS = "bison-native"