[OE-core] [PATCH][rocko] libnl: protect against buffer overflow (CVE-2017-0553)

[Ross Burton]

Signed-off-by: Ross Burton <ross.burton at intel.com>
---
 meta/recipes-support/libnl/libnl/overflow.patch | 39 +++++++++++++++++++++++++
 meta/recipes-support/libnl/libnl_3.2.29.bb      |  1 +
 2 files changed, 40 insertions(+)
 create mode 100644 meta/recipes-support/libnl/libnl/overflow.patch

diff --git a/meta/recipes-support/libnl/libnl/overflow.patch b/meta/recipes-support/libnl/libnl/overflow.patch
new file mode 100644
index 00000000000..777fac3ea1a
--- /dev/null
+++ b/meta/recipes-support/libnl/libnl/overflow.patch
@@ -0,0 +1,39 @@
+CVE: CVE-2017-0553
+Upstream-Status: Backport
+Signed-off-by: Ross Burton <ross.burton at intel.com>
+
+From 3e18948f17148e6a3c4255bdeaaf01ef6081ceeb Mon Sep 17 00:00:00 2001
+From: Thomas Haller <thaller at redhat.com>
+Date: Mon, 6 Feb 2017 22:23:52 +0100
+Subject: [PATCH] lib: check for integer-overflow in nlmsg_reserve()
+
+In general, libnl functions are not robust against calling with
+invalid arguments. Thus, never call libnl functions with invalid
+arguments. In case of nlmsg_reserve() this means never provide
+a @len argument that causes overflow.
+
+Still, add an additional safeguard to avoid exploiting such bugs.
+
+Assume that @pad is a trusted, small integer.
+Assume that n->nm_size is a valid number of allocated bytes (and thus
+much smaller then SIZE_T_MAX).
+Assume, that @len may be set to an untrusted value. Then the patch
+avoids an integer overflow resulting in reserving too few bytes.
+---
+ lib/msg.c | 3 +++
+ 1 file changed, 3 insertions(+)
+
+diff --git a/lib/msg.c b/lib/msg.c
+index 9af3f3a0..3e27d4e0 100644
+--- a/lib/msg.c
++++ b/lib/msg.c
+@@ -411,6 +411,9 @@ void *nlmsg_reserve(struct nl_msg *n, size_t len, int pad)
+ 	size_t nlmsg_len = n->nm_nlh->nlmsg_len;
+ 	size_t tlen;
+ 
++	if (len > n->nm_size)
++		return NULL;
++
+ 	tlen = pad ? ((len + (pad - 1)) & ~(pad - 1)) : len;
+ 
+ 	if ((tlen + nlmsg_len) > n->nm_size)
\ No newline at end of file
diff --git a/meta/recipes-support/libnl/libnl_3.2.29.bb b/meta/recipes-support/libnl/libnl_3.2.29.bb
index 7d4839ba506..746fd3d4153 100644
--- a/meta/recipes-support/libnl/libnl_3.2.29.bb
+++ b/meta/recipes-support/libnl/libnl_3.2.29.bb
@@ -12,6 +12,7 @@ DEPENDS = "flex-native bison-native"
 SRC_URI = "https://github.com/thom311/${BPN}/releases/download/${BPN}${@d.getVar('PV').replace('.','_')}/${BP}.tar.gz \
            file://fix-pktloc_syntax_h-race.patch \
            file://fix-pc-file.patch \
+           file://overflow.patch \
 "
 UPSTREAM_CHECK_URI = "https://github.com/thom311/${BPN}/releases"
 
-- 
2.11.0