libmad: patch CVE-2017-8372 and CVE-2017-8373

Pick patch [1] from Debian based on [2] and [3].

[1] https://salsa.debian.org/multimedia-team/libmad/-/blob/debian/0.15.1b-11/debian/patches/md_size.diff?ref_type=tags
[2] https://security-tracker.debian.org/tracker/CVE-2017-8372
[3] https://security-tracker.debian.org/tracker/CVE-2017-8373

Signed-off-by: Peter Marko <peter.marko@siemens.com>
Signed-off-by: Khem Raj <raj.khem@gmail.com>

2 files changed, 70 insertions, 0 deletions

diff --git a/meta-oe/recipes-multimedia/libmad/libmad/CVE-2017-8372_CVE-2017-8373.patch b/meta-oe/recipes-multimedia/libmad/libmad/CVE-2017-8372_CVE-2017-8373.patch
new file mode 100644
index 0000000000..a57df492d0
--- /dev/null
+++ b/meta-oe/recipes-multimedia/libmad/libmad/CVE-2017-8372_CVE-2017-8373.patch
@@ -0,0 +1,69 @@
+From 7e8f6e5118e31455924940141a761a1589e8d85d Mon Sep 17 00:00:00 2001
+From: Kurt Roeckx <kurt@roeckx.be>
+Date: Sun, 28 Jan 2018 15:44:08 +0100
+Subject: [PATCH] Check the size of the main data
+
+The main data to decode a frame can come from the current frame and part of the
+previous frame, the so called bit reservoir. si.main_data_begin is the part of
+the previous frame we need for this frame. frame_space is the amount of main
+data that can be in this frame, and next_md_begin is the part of this frame that
+is going to be used for the next frame.
+
+The maximum amount of data from a previous frame that the format allows is 511
+bytes. The maximum frame size for the defined bitrates is at MPEG 2.5 layer 2
+at 320 kbit/s and 8 kHz sample rate which gives 72 * (320000 / 8000) + 1 = 2881.
+So those defines are not large enough:
+ # define MAD_BUFFER_GUARD      8
+ # define MAD_BUFFER_MDLEN      (511 + 2048 + MAD_BUFFER_GUARD)
+
+There is also support for a "free" bitrate which allows you to create any frame
+size, which can be larger than the buffer.
+
+Changing the defines is not an option since it's part of the ABI, so we check
+that the main data fits in the bufer.
+
+The previous frame data is stored in *stream->main_data and contains
+stream->md_len bytes. If stream->md_len is larger than the data we
+need from the previous frame (si.main_data_begin) it still wouldn't fit
+in the buffer, so just keep the data that we need.
+
+Source: https://salsa.debian.org/multimedia-team/libmad/-/blob/debian/0.15.1b-11/debian/patches/md_size.diff?ref_type=tags
+
+CVE: CVE-2017-8372
+CVE: CVE-2017-8373
+Upstream-Status: Inactive-Upstream [lastrelease: 2018]
+Signed-off-by: Peter Marko <peter.marko@siemens.com>
+---
+ layer3.c | 12 ++++++++++--
+ 1 file changed, 10 insertions(+), 2 deletions(-)
+
+diff --git a/layer3.c b/layer3.c
+index 4e5d3fa..7dc4ca6 100644
+--- a/layer3.c
++++ b/layer3.c
+@@ -2608,6 +2608,11 @@ int mad_layer_III(struct mad_stream *stream, struct mad_frame *frame)
+     next_md_begin = 0;
+ 
+   md_len = si.main_data_begin + frame_space - next_md_begin;
++  if (md_len + MAD_BUFFER_GUARD > MAD_BUFFER_MDLEN) {
++    stream->error = MAD_ERROR_LOSTSYNC;
++    stream->sync = 0;
++    return -1;
++  }
+ 
+   frame_used = 0;
+ 
+@@ -2625,8 +2630,11 @@ int mad_layer_III(struct mad_stream *stream, struct mad_frame *frame)
+       }
+     }
+     else {
+-      mad_bit_init(&ptr,
+-                  *stream->main_data + stream->md_len - si.main_data_begin);
++      memmove(stream->main_data,
++       *stream->main_data + stream->md_len - si.main_data_begin,
++       si.main_data_begin);
++      stream->md_len = si.main_data_begin;
++      mad_bit_init(&ptr, *stream->main_data);
+ 
+       if (md_len > si.main_data_begin) {
+        assert(stream->md_len + md_len -
diff --git a/meta-oe/recipes-multimedia/libmad/libmad_0.15.1b.bb b/meta-oe/recipes-multimedia/libmad/libmad_0.15.1b.bb
index 2d63f9a804..b6668980da 100644
--- a/meta-oe/recipes-multimedia/libmad/libmad_0.15.1b.bb
+++ b/meta-oe/recipes-multimedia/libmad/libmad_0.15.1b.bb
@@ -16,6 +16,7 @@ SRC_URI = "https://downloads.sourceforge.net/mad/libmad-${PV}.tar.gz \
     file://obsolete_automake_macros.patch \
     file://automake-foreign.patch \
     file://0001-configure-Respect-the-cflags-from-environment.patch \
+    file://CVE-2017-8372_CVE-2017-8373.patch \
 "
 SRC_URI:append:toolchain-clang = " file://0004-Remove-clang-unsupported-compiler-flags.patch "