Alexandre Julliard : gdi32: Limit line drawing coordinates to reasonable values to avoid overflows.
Alexandre Julliard
julliard at winehq.org
Mon Jul 30 14:18:51 CDT 2012
Module: wine
Branch: master
Commit: a9151e5da3a2633505d21a3af86d2f11fb5c58a0
URL: http://source.winehq.org/git/wine.git/?a=commit;h=a9151e5da3a2633505d21a3af86d2f11fb5c58a0
Author: Alexandre Julliard <julliard at winehq.org>
Date: Mon Jul 30 12:47:24 2012 +0200
gdi32: Limit line drawing coordinates to reasonable values to avoid overflows.
---
dlls/gdi32/dibdrv/objects.c | 27 ++++++++++++++++++++-------
1 files changed, 20 insertions(+), 7 deletions(-)
diff --git a/dlls/gdi32/dibdrv/objects.c b/dlls/gdi32/dibdrv/objects.c
index 026ea50..0292537 100644
--- a/dlls/gdi32/dibdrv/objects.c
+++ b/dlls/gdi32/dibdrv/objects.c
@@ -300,6 +300,17 @@ static inline DWORD calc_outcode(const POINT *pt, const RECT *clip)
return out;
}
+/* crop coordinates to a reasonable range to avoid overflows in calculations */
+static inline POINT crop_coords( POINT pt )
+{
+ if (pt.x >= 0x10000000 || pt.x <= -0x10000000 || pt.y >= 0x10000000 || pt.y <= -0x10000000)
+ {
+ pt.x /= 8;
+ pt.y /= 8;
+ }
+ return pt;
+}
+
static void init_bres_params( const POINT *start, const POINT *end, bres_params *clip_params,
struct line_params *line_params, RECT *rect )
{
@@ -603,6 +614,7 @@ static BOOL solid_pen_line(dibdrv_physdev *pdev, POINT *start, POINT *end, DWORD
{
bres_params clip_params;
struct line_params line_params;
+ POINT p1 = crop_coords( *start ), p2 = crop_coords( *end );
init_bres_params( start, end, &clip_params, &line_params, &rect );
if (!get_clipped_rects( &pdev->dib, &rect, pdev->clip, &clipped_rects )) return TRUE;
@@ -611,11 +623,11 @@ static BOOL solid_pen_line(dibdrv_physdev *pdev, POINT *start, POINT *end, DWORD
POINT clipped_start, clipped_end;
int clip_status;
- clip_status = clip_line(start, end, clipped_rects.rects + i, &clip_params, &clipped_start, &clipped_end);
+ clip_status = clip_line( &p1, &p2, clipped_rects.rects + i, &clip_params, &clipped_start, &clipped_end);
if(clip_status)
{
- int m = abs(clipped_start.x - start->x);
- int n = abs(clipped_start.y - start->y);
+ int m = abs(clipped_start.x - p1.x);
+ int n = abs(clipped_start.y - p1.y);
if (line_params.x_major)
{
@@ -630,7 +642,7 @@ static BOOL solid_pen_line(dibdrv_physdev *pdev, POINT *start, POINT *end, DWORD
line_params.length = abs( clipped_end.y - clipped_start.y ) + 1;
}
- if (clipped_end.x == end->x && clipped_end.y == end->y) line_params.length--;
+ if (clipped_end.x == p2.x && clipped_end.y == p2.y) line_params.length--;
pdev->dib.funcs->solid_line( &pdev->dib, &clipped_start, &line_params, and, xor );
@@ -987,6 +999,7 @@ static BOOL dashed_pen_line(dibdrv_physdev *pdev, POINT *start, POINT *end)
{
bres_params clip_params;
struct line_params line_params;
+ POINT p1 = crop_coords( *start ), p2 = crop_coords( *end );
init_bres_params( start, end, &clip_params, &line_params, &rect );
get_clipped_rects( &pdev->dib, &rect, pdev->clip, &clipped_rects );
@@ -994,12 +1007,12 @@ static BOOL dashed_pen_line(dibdrv_physdev *pdev, POINT *start, POINT *end)
{
POINT clipped_start, clipped_end;
int clip_status;
- clip_status = clip_line(start, end, clipped_rects.rects + i, &clip_params, &clipped_start, &clipped_end);
+ clip_status = clip_line(&p1, &p2, clipped_rects.rects + i, &clip_params, &clipped_start, &clipped_end);
if(clip_status)
{
- int m = abs(clipped_start.x - start->x);
- int n = abs(clipped_start.y - start->y);
+ int m = abs(clipped_start.x - p1.x);
+ int n = abs(clipped_start.y - p1.y);
pdev->dash_pos = start_pos;
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