dev-games/godot: fix CVE-2021-26825

An integer overflow issue exists in Godot Engine up to v3.2 that can
be triggered when loading specially crafted.TGA image files. The
vulnerability exists in ImageLoaderTGA::load_image() function at line:

const size_t buffer_size = (tga_header.image_width * tga_header.image_height) * pixel_size;

The bug leads to Dynamic stack buffer overflow. Depending on the
context of the application, attack vector can be local or remote,
and can lead to code execution and/or system crash.

Reference: https://nvd.nist.gov/vuln/detail/CVE-2021-26825
Reference: https://github.com/godotengine/godot/pull/45702
Closes: https://bugs.gentoo.org/769761
Package-Manager: Portage-3.0.14, Repoman-3.0.2
Signed-off-by: Ross Charles Campbell <rossbridger.cc@gmail.com>

2 files changed, 112 insertions, 1 deletions

diff --git a/dev-games/godot/files/godot-3.2.3-fix-CVE-2021-26825.patch b/dev-games/godot/files/godot-3.2.3-fix-CVE-2021-26825.patch
new file mode 100644
index 0000000000..e2602f5ee6
--- /dev/null
+++ b/dev-games/godot/files/godot-3.2.3-fix-CVE-2021-26825.patch
@@ -0,0 +1,108 @@
+commit 113b5ab1c45c01b8e6d54d13ac8876d091f883a8
+Author: Hein-Pieter van Braam-Stewart <hp@tmm.cx>
+Date:   Thu Feb 4 12:56:33 2021 +0100
+
+    Fix a crash in the TGA loader with malformed input
+
+diff --git a/modules/tga/image_loader_tga.cpp b/modules/tga/image_loader_tga.cpp
+index d60efdd5bc..964dc091a7 100644
+--- a/modules/tga/image_loader_tga.cpp
++++ b/modules/tga/image_loader_tga.cpp
+@@ -55,6 +55,10 @@ Error ImageLoaderTGA::decode_tga_rle(const uint8_t *p_compressed_buffer, size_t
+ 		compressed_pos += 1;
+ 		count = (c & 0x7f) + 1;
+ 
++		if (output_pos + count * p_pixel_size > output_pos) {
++			return ERR_PARSE_ERROR;
++		}
++
+ 		if (c & 0x80) {
+ 			for (size_t i = 0; i < p_pixel_size; i++) {
+ 				pixels_w.ptr()[i] = p_compressed_buffer[compressed_pos];
+@@ -78,7 +82,7 @@ Error ImageLoaderTGA::decode_tga_rle(const uint8_t *p_compressed_buffer, size_t
+ 	return OK;
+ }
+ 
+-Error ImageLoaderTGA::convert_to_image(Ref<Image> p_image, const uint8_t *p_buffer, const tga_header_s &p_header, const uint8_t *p_palette, const bool p_is_monochrome) {
++Error ImageLoaderTGA::convert_to_image(Ref<Image> p_image, const uint8_t *p_buffer, const tga_header_s &p_header, const uint8_t *p_palette, const bool p_is_monochrome, size_t p_output_size) {
+ 
+ #define TGA_PUT_PIXEL(r, g, b, a)             \
+ 	int image_data_ofs = ((y * width) + x);   \
+@@ -130,6 +134,9 @@ Error ImageLoaderTGA::convert_to_image(Ref<Image> p_image, const uint8_t *p_buff
+ 		if (p_is_monochrome) {
+ 			while (y != y_end) {
+ 				while (x != x_end) {
++					if (i > p_output_size) {
++						return ERR_PARSE_ERROR;
++					}
+ 					uint8_t shade = p_buffer[i];
+ 
+ 					TGA_PUT_PIXEL(shade, shade, shade, 0xff)
+@@ -143,6 +150,9 @@ Error ImageLoaderTGA::convert_to_image(Ref<Image> p_image, const uint8_t *p_buff
+ 		} else {
+ 			while (y != y_end) {
+ 				while (x != x_end) {
++					if (i > p_output_size) {
++						return ERR_PARSE_ERROR;
++					}
+ 					uint8_t index = p_buffer[i];
+ 					uint8_t r = 0x00;
+ 					uint8_t g = 0x00;
+@@ -171,6 +181,10 @@ Error ImageLoaderTGA::convert_to_image(Ref<Image> p_image, const uint8_t *p_buff
+ 	} else if (p_header.pixel_depth == 24) {
+ 		while (y != y_end) {
+ 			while (x != x_end) {
++				if (i + 2 > p_output_size) {
++					return ERR_PARSE_ERROR;
++				}
++
+ 				uint8_t r = p_buffer[i + 2];
+ 				uint8_t g = p_buffer[i + 1];
+ 				uint8_t b = p_buffer[i + 0];
+@@ -186,6 +200,10 @@ Error ImageLoaderTGA::convert_to_image(Ref<Image> p_image, const uint8_t *p_buff
+ 	} else if (p_header.pixel_depth == 32) {
+ 		while (y != y_end) {
+ 			while (x != x_end) {
++				if (i + 3 > p_output_size) {
++					return ERR_PARSE_ERROR;
++				}
++
+ 				uint8_t a = p_buffer[i + 3];
+ 				uint8_t r = p_buffer[i + 2];
+ 				uint8_t g = p_buffer[i + 1];
+@@ -280,7 +298,7 @@ Error ImageLoaderTGA::load_image(Ref<Image> p_image, FileAccess *f, bool p_force
+ 		PoolVector<uint8_t>::Read src_image_r = src_image.read();
+ 
+ 		const size_t pixel_size = tga_header.pixel_depth >> 3;
+-		const size_t buffer_size = (tga_header.image_width * tga_header.image_height) * pixel_size;
++		size_t buffer_size = (tga_header.image_width * tga_header.image_height) * pixel_size;
+ 
+ 		PoolVector<uint8_t> uncompressed_buffer;
+ 		uncompressed_buffer.resize(buffer_size);
+@@ -299,11 +317,12 @@ Error ImageLoaderTGA::load_image(Ref<Image> p_image, FileAccess *f, bool p_force
+ 			}
+ 		} else {
+ 			buffer = src_image_r.ptr();
++			buffer_size = src_image_len;
+ 		};
+ 
+ 		if (err == OK) {
+ 			PoolVector<uint8_t>::Read palette_r = palette.read();
+-			err = convert_to_image(p_image, buffer, tga_header, palette_r.ptr(), is_monochrome);
++			err = convert_to_image(p_image, buffer, tga_header, palette_r.ptr(), is_monochrome, buffer_size);
+ 		}
+ 	}
+ 
+diff --git a/modules/tga/image_loader_tga.h b/modules/tga/image_loader_tga.h
+index 249e33411e..bbfc3fed32 100644
+--- a/modules/tga/image_loader_tga.h
++++ b/modules/tga/image_loader_tga.h
+@@ -73,7 +73,7 @@ class ImageLoaderTGA : public ImageFormatLoader {
+ 		uint8_t image_descriptor;
+ 	};
+ 	static Error decode_tga_rle(const uint8_t *p_compressed_buffer, size_t p_pixel_size, uint8_t *p_uncompressed_buffer, size_t p_output_size);
+-	static Error convert_to_image(Ref<Image> p_image, const uint8_t *p_buffer, const tga_header_s &p_header, const uint8_t *p_palette, const bool p_is_monochrome);
++	static Error convert_to_image(Ref<Image> p_image, const uint8_t *p_buffer, const tga_header_s &p_header, const uint8_t *p_palette, const bool p_is_monochrome, size_t p_output_size);
+ 
+ public:
+ 	virtual Error load_image(Ref<Image> p_image, FileAccess *f, bool p_force_linear, float p_scale);
diff --git a/dev-games/godot/godot-3.2.3.ebuild b/dev-games/godot/godot-3.2.3-r1.ebuild
index 05980a2d11..f978022fe9 100644
--- a/dev-games/godot/godot-3.2.3.ebuild
+++ b/dev-games/godot/godot-3.2.3-r1.ebuild
@@ -54,7 +54,10 @@ DEPEND="
 "
 BDEPEND="virtual/pkgconfig"
 
-PATCHES=( "${FILESDIR}"/${P}-fix-llvm-build.patch )
+PATCHES=(
+	"${FILESDIR}"/${P}-fix-llvm-build.patch
+	"${FILESDIR}"/${P}-fix-CVE-2021-26825.patch
+)
 
 src_prepare() {
 	default