From mboxrd@z Thu Jan 1 00:00:00 1970 From: Roel Kluin <12o3l@tiscali.nl> Subject: [PATCH] atafb: test virtual screen range before subtraction on unsigned Date: Wed, 23 Apr 2008 20:51:14 +0200 Message-ID: <480F8522.4090805@tiscali.nl> References: <480F6FF9.9000605@tiscali.nl> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <480F6FF9.9000605@tiscali.nl> Sender: linux-kernel-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii" To: adaplas@gmail.com, linux-fbdev-devel@lists.sourceforge.net Cc: lkml a bit similar to vga16fb, --- dx and dy are u32's, so the test should occur before the subtraction Signed-off-by: Roel Kluin <12o3l@tiscali.nl> --- 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)) {