cairo: backport patch for CVE-2020-35492

(From OE-Core rev: 907e0edecbef830e1b057c58f5d398b57529f085)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
(cherry picked from commit 0c4e6f99332ae253855708845a41fdfeb72d4c30)
Signed-off-by: Steve Sakoman <steve@sakoman.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-graphics/cairo/cairo/CVE-2020-35492.patch

@@ -0,0 +1,60 @@
+Fix stack buffer overflow.
+
+CVE: CVE-2020-35492
+Upstream-Status: Backport
+Signed-off-by: Ross Burton <ross.burton@arm.com>
+
+From 03a820b173ed1fdef6ff14b4468f5dbc02ff59be Mon Sep 17 00:00:00 2001
+From: Heiko Lewin <heiko.lewin@worldiety.de>
+Date: Tue, 15 Dec 2020 16:48:19 +0100
+Subject: [PATCH] Fix mask usage in image-compositor
+
+---
+ src/cairo-image-compositor.c                |   8 ++--
+ test/Makefile.sources                       |   1 +
+ test/bug-image-compositor.c                 |  39 ++++++++++++++++++++
+ test/reference/bug-image-compositor.ref.png | Bin 0 -> 185 bytes
+ 4 files changed, 44 insertions(+), 4 deletions(-)
+ create mode 100644 test/bug-image-compositor.c
+ create mode 100644 test/reference/bug-image-compositor.ref.png
+
+diff --git a/src/cairo-image-compositor.c b/src/cairo-image-compositor.c
+index 79ad69f68..4f8aaed99 100644
+--- a/src/cairo-image-compositor.c
++++ b/src/cairo-image-compositor.c
+@@ -2601,14 +2601,14 @@ _inplace_src_spans (void *abstract_renderer, int y, int h,
+ 		    unsigned num_spans)
+ {
+     cairo_image_span_renderer_t *r = abstract_renderer;
+-    uint8_t *m;
++    uint8_t *m, *base = (uint8_t*)pixman_image_get_data(r->mask);
+     int x0;
+ 
+     if (num_spans == 0)
+ 	return CAIRO_STATUS_SUCCESS;
+ 
+     x0 = spans[0].x;
+-    m = r->_buf;
++    m = base;
+     do {
+ 	int len = spans[1].x - spans[0].x;
+ 	if (len >= r->u.composite.run_length && spans[0].coverage == 0xff) {
+@@ -2655,7 +2655,7 @@ _inplace_src_spans (void *abstract_renderer, int y, int h,
+ 				      spans[0].x, y,
+ 				      spans[1].x - spans[0].x, h);
+ 
+-	    m = r->_buf;
++	    m = base;
+ 	    x0 = spans[1].x;
+ 	} else if (spans[0].coverage == 0x0) {
+ 	    if (spans[0].x != x0) {
+@@ -2684,7 +2684,7 @@ _inplace_src_spans (void *abstract_renderer, int y, int h,
+ #endif
+ 	    }
+ 
+-	    m = r->_buf;
++	    m = base;
+ 	    x0 = spans[1].x;
+ 	} else {
+ 	    *m++ = spans[0].coverage;
+-- 

meta/recipes-graphics/cairo/cairo_1.16.0.bb

@@ -27,6 +27,7 @@ SRC_URI = "http://cairographics.org/releases/cairo-${PV}.tar.xz \
            file://CVE-2018-19876.patch \
            file://CVE-2019-6461.patch \
            file://CVE-2019-6462.patch \
+           file://CVE-2020-35492.patch \
           "
 
 SRC_URI[md5sum] = "f19e0353828269c22bd72e271243a552"