libnl: fix CVE-2017-0553

An elevation of privilege vulnerability in libnl could enable a local
malicious application to execute arbitrary code within the context of
the Wi-Fi service. This issue is rated as Moderate because it first
requires compromising a privileged process and is mitigated by
current platform configurations. Product: Android. Versions: 5.0.2,
5.1.1, 6.0, 6.0.1, 7.0, 7.1.1. Android ID: A-32342065. NOTE: this
issue also exists in the upstream libnl before 3.3.0 library.

  https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-0553

Backport fix from upstream libnl 3.3.0 release:

  https://github.com/thom311/libnl/commit/3e18948f17148e6a3c4255bdeaaf01ef6081ceeb
  http://lists.infradead.org/pipermail/libnl/2017-May/002313.html

(From OE-Core rev: f452fbc5d2ffb9c1417079574bed0dfcdc44787a)

Signed-off-by: Andre McCurdy <armccurdy@gmail.com>
Signed-off-by: Armin Kuster <akuster808@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

2 files changed, 45 insertions, 0 deletions

diff --git a/meta/recipes-support/libnl/libnl/lib-check-for-integer-overflow-in-nlmsg_reserve.patch b/meta/recipes-support/libnl/libnl/lib-check-for-integer-overflow-in-nlmsg_reserve.patch
new file mode 100644
index 0000000000..594dd0616a
--- /dev/null
+++ b/meta/recipes-support/libnl/libnl/lib-check-for-integer-overflow-in-nlmsg_reserve.patch
@@ -0,0 +1,43 @@
+From 3e18948f17148e6a3c4255bdeaaf01ef6081ceeb Mon Sep 17 00:00:00 2001
+From: Thomas Haller <thaller@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.
+
+Upstream-Status: Backport [https://github.com/thom311/libnl/commit/3e18948f17148e6a3c4255bdeaaf01ef6081ceeb]
+CVE: CVE-2017-0553
+
+Signed-off-by: Andre McCurdy <armccurdy@gmail.com>
+---
+ lib/msg.c | 3 +++
+ 1 file changed, 3 insertions(+)
+
+diff --git a/lib/msg.c b/lib/msg.c
+index 9af3f3a..3e27d4e 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)
+-- 
+1.9.1
+
diff --git a/meta/recipes-support/libnl/libnl_3.2.29.bb b/meta/recipes-support/libnl/libnl_3.2.29.bb
index 7d4839ba50..4ce80e871b 100644
--- a/meta/recipes-support/libnl/libnl_3.2.29.bb
+++ b/meta/recipes-support/libnl/libnl_3.2.29.bb
@@ -12,7 +12,9 @@ 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://lib-check-for-integer-overflow-in-nlmsg_reserve.patch \
 "
+
 UPSTREAM_CHECK_URI = "https://github.com/thom311/${BPN}/releases"
 
 SRC_URI[md5sum] = "a8ba62a5c4f883f4e493a46d1f3733fe"