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

[Andre McCurdy]

On Wed, May 16, 2018 at 4:30 PM, Ross Burton <ross.burton at intel.com> wrote:

Looks like a duplicate of:

  http://lists.openembedded.org/pipermail/openembedded-core/2018-May/150743.html

?

> 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
>
> --
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