Blame SOURCES/Add-checks-for-bitmap-and-glyph-width-heigth-values.patch

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From 4a4ecc32b160e93ee1e37e5617a0197e2d022643 Mon Sep 17 00:00:00 2001
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From: Armin Novak <armin.novak@thincast.com>
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Date: Thu, 4 Nov 2021 11:07:41 +0100
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Subject: [PATCH] Add checks for bitmap and glyph width/heigth values
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CVE-2021-41160
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https://github.com/FreeRDP/FreeRDP/pull/7349
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Signed-off-by: Felipe Borges <felipeborges@gnome.org>
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---
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 libfreerdp/core/orders.c  | 14 ++++++++++++
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 libfreerdp/core/surface.c | 45 +++++++++++++++++++++++++++++++++++++++
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 libfreerdp/core/update.c  |  7 ++++++
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 3 files changed, 66 insertions(+)
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diff --git a/libfreerdp/core/orders.c b/libfreerdp/core/orders.c
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index 74870fae6..44d23a61a 100644
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--- a/libfreerdp/core/orders.c
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+++ b/libfreerdp/core/orders.c
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@@ -1848,6 +1848,13 @@ static BOOL update_read_fast_glyph_order(wStream* s, const ORDER_INFO* orderInfo
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 			new_cb = ((glyph->cx + 7) / 8) * glyph->cy;
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 			new_cb += ((new_cb % 4) > 0) ? 4 - (new_cb % 4) : 0;
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+			if ((glyph->cx == 0) || (glyph->cy == 0))
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+			{
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+				WLog_ERR(TAG, "GLYPH_DATA_V2::cx=%" PRIu32 ", GLYPH_DATA_V2::cy=%" PRIu32,
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+				         glyph->cx, glyph->cy);
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+				return FALSE;
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+			}
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+
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 			if (fastGlyph->cbData < new_cb)
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 				return FALSE;
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@@ -2825,6 +2832,13 @@ update_read_create_offscreen_bitmap_order(wStream* s,
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 	Stream_Read_UINT16(s, create_offscreen_bitmap->cy); /* cy (2 bytes) */
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 	deleteList = &(create_offscreen_bitmap->deleteList);
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+	if ((create_offscreen_bitmap->cx == 0) || (create_offscreen_bitmap->cy == 0))
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+	{
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+		WLog_ERR(TAG, "Invalid OFFSCREEN_DELETE_LIST: cx=%" PRIu16 ", cy=%" PRIu16,
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+		         create_offscreen_bitmap->cx, create_offscreen_bitmap->cy);
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+		return FALSE;
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+	}
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+
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 	if (deleteListPresent)
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 	{
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 		UINT32 i;
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diff --git a/libfreerdp/core/surface.c b/libfreerdp/core/surface.c
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index d5c709885..ca89d230c 100644
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--- a/libfreerdp/core/surface.c
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+++ b/libfreerdp/core/surface.c
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@@ -21,6 +21,8 @@
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 #include "config.h"
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 #endif
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+#include <assert.h>
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+
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 #include <freerdp/utils/pcap.h>
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 #include <freerdp/log.h>
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@@ -62,6 +64,13 @@ static BOOL update_recv_surfcmd_bitmap_ex(wStream* s, TS_BITMAP_DATA_EX* bmp)
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 	Stream_Read_UINT16(s, bmp->height);
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 	Stream_Read_UINT32(s, bmp->bitmapDataLength);
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+	if ((bmp->width == 0) || (bmp->height == 0))
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+	{
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+		WLog_ERR(TAG, "invalid size value width=%" PRIu16 ", height=%" PRIu16, bmp->width,
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+		         bmp->height);
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+		return FALSE;
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+	}
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+
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 	if ((bmp->bpp < 1) || (bmp->bpp > 32))
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 	{
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 		WLog_ERR(TAG, "invalid bpp value %" PRIu32 "", bmp->bpp);
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@@ -85,6 +94,39 @@ static BOOL update_recv_surfcmd_bitmap_ex(wStream* s, TS_BITMAP_DATA_EX* bmp)
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 	return TRUE;
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 }
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+static BOOL update_recv_surfcmd_is_rect_valid(const rdpContext* context,
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+                                              const SURFACE_BITS_COMMAND* cmd)
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+{
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+	assert(context);
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+	assert(context->settings);
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+	assert(cmd);
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+
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+	/* We need a rectangle with left/top being smaller than right/bottom.
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+	 * Also do not allow empty rectangles. */
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+	if ((cmd->destTop >= cmd->destBottom) || (cmd->destLeft >= cmd->destRight))
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+	{
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+		WLog_WARN(TAG,
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+		          "Empty surface bits command rectangle: %" PRIu16 "x%" PRIu16 "-%" PRIu16
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+		          "x%" PRIu16,
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+		          cmd->destLeft, cmd->destTop, cmd->destRight, cmd->destBottom);
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+		return FALSE;
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+	}
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+
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+	/* The rectangle needs to fit into our session size */
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+	if ((cmd->destRight > context->settings->DesktopWidth) ||
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+	    (cmd->destBottom > context->settings->DesktopHeight))
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+	{
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+		WLog_WARN(TAG,
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+		          "Invalid surface bits command rectangle: %" PRIu16 "x%" PRIu16 "-%" PRIu16
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+		          "x%" PRIu16 " does not fit %" PRIu32 "x%" PRIu32,
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+		          cmd->destLeft, cmd->destTop, cmd->destRight, cmd->destBottom,
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+		          context->settings->DesktopWidth, context->settings->DesktopHeight);
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+		return FALSE;
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+	}
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+
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+	return TRUE;
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+}
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+
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 static BOOL update_recv_surfcmd_surface_bits(rdpUpdate* update, wStream* s, UINT16 cmdType)
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 {
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 	SURFACE_BITS_COMMAND cmd = { 0 };
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@@ -98,6 +140,9 @@ static BOOL update_recv_surfcmd_surface_bits(rdpUpdate* update, wStream* s, UINT
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 	Stream_Read_UINT16(s, cmd.destRight);
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 	Stream_Read_UINT16(s, cmd.destBottom);
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+	if (!update_recv_surfcmd_is_rect_valid(update->context, &cmd))
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+		goto fail;
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+
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 	if (!update_recv_surfcmd_bitmap_ex(s, &cmd.bmp))
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 		goto fail;
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diff --git a/libfreerdp/core/update.c b/libfreerdp/core/update.c
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index ebb82fc2d..e137c3de8 100644
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--- a/libfreerdp/core/update.c
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+++ b/libfreerdp/core/update.c
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@@ -99,6 +99,13 @@ static BOOL update_read_bitmap_data(rdpUpdate* update, wStream* s, BITMAP_DATA*
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 	Stream_Read_UINT16(s, bitmapData->flags);
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 	Stream_Read_UINT16(s, bitmapData->bitmapLength);
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+	if ((bitmapData->width == 0) || (bitmapData->height == 0))
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+	{
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+		WLog_ERR(TAG, "Invalid BITMAP_DATA: width=%" PRIu16 ", height=%" PRIu16, bitmapData->width,
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+		         bitmapData->height);
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+		return FALSE;
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+	}
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+
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 	if (bitmapData->flags & BITMAP_COMPRESSION)
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 	{
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 		if (!(bitmapData->flags & NO_BITMAP_COMPRESSION_HDR))
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-- 
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2.32.0
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