Re: [PATCH] atafb: test virtual screen range before subtraction on unsigned
From: Geert Uytterhoeven <geert@linux-m68k.org>
Date: 2008-04-24 21:06:18
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On Wed, 23 Apr 2008, Roel Kluin wrote:
a bit similar to vga16fb, --- dx and dy are u32's, so the test should occur before the subtraction
Note that fb_copyarea.d[xy] are also u32, while there are many tests that check for these fields being negative.
quoted hunk ↗ jump to hunk
Signed-off-by: Roel Kluin <redacted> ---diff --git a/drivers/video/atafb.c b/drivers/video/atafb.c index 5d4fbaa..8f60a8f 100644 --- a/drivers/video/atafb.c +++ b/drivers/video/atafb.c@@ -2593,13 +2593,16 @@ static void atafb_copyarea(struct fb_info *info, const struct fb_copyarea *area) width = x2 - dx; height = y2 - dy; + if (area->sx + dx < area->dx || area->sy + dy < area->dy) + return; + /* update sx,sy */ sx = area->sx + (dx - area->dx); sy = area->sy + (dy - area->dy); /* the source must be completely inside the virtual screen */ - if (sx < 0 || sy < 0 || (sx + width) > info->var.xres_virtual || - (sy + height) > info->var.yres_virtual) + if (sx + width > info->var.xres_virtual || + sy + height > info->var.yres_virtual) return; if (dy > sy || (dy == sy && dx > sx)) {
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
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