From ee99fe4088d0c75b3d2cfcd321d8af60b8fc959a Mon Sep 17 00:00:00 2001 From: Peter Korsgaard Date: Mon, 28 Nov 2016 22:55:38 +0100 Subject: [PATCH] gst1-plugins-bad: add upstream patch to fix security issue in vmnc decoder As detailed by Chris Evans, the vmnc decoder contains an integer overflow which can be exploited: https://scarybeastsecurity.blogspot.be/2016/11/0day-poc-risky-design-decisions-in.html Fixes CVE-2016-9445 and CVE-2016-9446. Signed-off-by: Peter Korsgaard --- ...y-check-width-height-before-using-it.patch | 51 +++++++++++++++++++ 1 file changed, 51 insertions(+) create mode 100644 package/gstreamer1/gst1-plugins-bad/0001-vmncdec-Sanity-check-width-height-before-using-it.patch diff --git a/package/gstreamer1/gst1-plugins-bad/0001-vmncdec-Sanity-check-width-height-before-using-it.patch b/package/gstreamer1/gst1-plugins-bad/0001-vmncdec-Sanity-check-width-height-before-using-it.patch new file mode 100644 index 0000000000..ebc87bb9e9 --- /dev/null +++ b/package/gstreamer1/gst1-plugins-bad/0001-vmncdec-Sanity-check-width-height-before-using-it.patch @@ -0,0 +1,51 @@ +From 465091253bb3c3198d055b2e9f02d95237204663 Mon Sep 17 00:00:00 2001 +From: =?UTF-8?q?Sebastian=20Dr=C3=B6ge?= +Date: Wed, 16 Nov 2016 20:41:39 +0200 +Subject: [PATCH] vmncdec: Sanity-check width/height before using it + +We will allocate a screen area of width*height*bpp bytes, however this +calculation can easily overflow if too high width or height are given +inside the stream. Nonetheless we would just assume that enough memory +was allocated, try to fill it and overwrite as much memory as wanted. + +Also allocate the screen area filled with zeroes to ensure that we start +with full-black and not any random (or not so random) data. + +https://scarybeastsecurity.blogspot.gr/2016/11/0day-poc-risky-design-decisions-in.html + +Ideally we should just remove this plugin in favour of the one in +gst-libav, which generally seems to be of better code quality. + +https://bugzilla.gnome.org/show_bug.cgi?id=774533 +Signed-off-by: Peter Korsgaard +--- + gst/vmnc/vmncdec.c | 6 +++++- + 1 file changed, 5 insertions(+), 1 deletion(-) + +diff --git a/gst/vmnc/vmncdec.c b/gst/vmnc/vmncdec.c +index 5504302..a843136 100644 +--- a/gst/vmnc/vmncdec.c ++++ b/gst/vmnc/vmncdec.c +@@ -261,7 +261,7 @@ vmnc_handle_wmvi_rectangle (GstVMncDec * dec, struct RfbRectangle *rect, + gst_video_codec_state_unref (state); + + g_free (dec->imagedata); +- dec->imagedata = g_malloc (dec->format.width * dec->format.height * ++ dec->imagedata = g_malloc0 (dec->format.width * dec->format.height * + dec->format.bytes_per_pixel); + GST_DEBUG_OBJECT (dec, "Allocated image data at %p", dec->imagedata); + +@@ -791,6 +791,10 @@ vmnc_handle_packet (GstVMncDec * dec, const guint8 * data, int len, + GST_WARNING_OBJECT (dec, "Rectangle out of range, type %d", r.type); + return ERROR_INVALID; + } ++ } else if (r.width > 16384 || r.height > 16384) { ++ GST_WARNING_OBJECT (dec, "Width or height too high: %ux%u", r.width, ++ r.height); ++ return ERROR_INVALID; + } + + switch (r.type) { +-- +2.10.2 + -- 2.30.2