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From: BALATON Zoltan <balaton@eik.bme.hu>
To: Gerd Hoffmann <kraxel@redhat.com>
Cc: Intel.Product.Security.Incident.Response.Team@intel.com,
	pmatouse@redhat.com, qemu-devel@nongnu.org,
	qemu-stable@nongnu.org
Subject: Re: [Qemu-devel] [PATCH 3/5] vmware-vga: use vmsvga_verify_rect in vmsvga_update_rect
Date: Tue, 14 Oct 2014 11:29:13 +0200 (CEST)	[thread overview]
Message-ID: <alpine.LMD.2.02.1410141126051.13267@jedlik.phy.bme.hu> (raw)
In-Reply-To: <1413272710-10458-4-git-send-email-kraxel@redhat.com>

On Tue, 14 Oct 2014, Gerd Hoffmann wrote:
> Switch vmsvga_update_rect over to use vmsvga_verify_rect.  Slight change
> in behavior:  We don't try to automatically fixup rectangles any more.
> Invalid update requests will be ignored instead.

Are you sure this won't break clients? I remember that maybe Windows 
drivers did produce requests with partially off screen rectangles for 
objects that are partially visible. I don't recall if this was for windows 
dragged off screen or mouse pointer near the screen but there was a reason 
this fixup was added. Did you test this?

Regards,
BALATON Zoltan

>
> Cc: qemu-stable@nongnu.org
> Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
> ---
> hw/display/vmware_vga.c | 32 ++------------------------------
> 1 file changed, 2 insertions(+), 30 deletions(-)
>
> diff --git a/hw/display/vmware_vga.c b/hw/display/vmware_vga.c
> index fc0a2a7..7564f88 100644
> --- a/hw/display/vmware_vga.c
> +++ b/hw/display/vmware_vga.c
> @@ -356,36 +356,8 @@ static inline void vmsvga_update_rect(struct vmsvga_state_s *s,
>     uint8_t *src;
>     uint8_t *dst;
>
> -    if (x < 0) {
> -        fprintf(stderr, "%s: update x was < 0 (%d)\n", __func__, x);
> -        w += x;
> -        x = 0;
> -    }
> -    if (w < 0) {
> -        fprintf(stderr, "%s: update w was < 0 (%d)\n", __func__, w);
> -        w = 0;
> -    }
> -    if (x + w > surface_width(surface)) {
> -        fprintf(stderr, "%s: update width too large x: %d, w: %d\n",
> -                __func__, x, w);
> -        x = MIN(x, surface_width(surface));
> -        w = surface_width(surface) - x;
> -    }
> -
> -    if (y < 0) {
> -        fprintf(stderr, "%s: update y was < 0 (%d)\n",  __func__, y);
> -        h += y;
> -        y = 0;
> -    }
> -    if (h < 0) {
> -        fprintf(stderr, "%s: update h was < 0 (%d)\n",  __func__, h);
> -        h = 0;
> -    }
> -    if (y + h > surface_height(surface)) {
> -        fprintf(stderr, "%s: update height too large y: %d, h: %d\n",
> -                __func__, y, h);
> -        y = MIN(y, surface_height(surface));
> -        h = surface_height(surface) - y;
> +    if (!vmsvga_verify_rect(surface, __func__, x, y, w, h)) {
> +        return;
>     }
>
>     bypl = surface_stride(surface);
> -- 
> 1.8.3.1
>
>
>

  reply	other threads:[~2014-10-14  9:36 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-10-14  7:45 [Qemu-devel] [PATCH 0/5] vmware-vga: fix CVE-2014-3689 Gerd Hoffmann
2014-10-14  7:45 ` [Qemu-devel] [PATCH 1/5] vmware-vga: CVE-2014-3689: turn off hw accel Gerd Hoffmann
2014-10-14  7:45 ` [Qemu-devel] [PATCH 2/5] vmware-vga: add vmsvga_verify_rect Gerd Hoffmann
2014-10-14  9:24   ` Gonglei
2014-10-14  7:45 ` [Qemu-devel] [PATCH 3/5] vmware-vga: use vmsvga_verify_rect in vmsvga_update_rect Gerd Hoffmann
2014-10-14  9:29   ` BALATON Zoltan [this message]
2014-10-14 10:08     ` Gerd Hoffmann
2014-10-14  7:45 ` [Qemu-devel] [PATCH 4/5] vmware-vga: use vmsvga_verify_rect in vmsvga_copy_rect Gerd Hoffmann
2014-10-14  7:45 ` [Qemu-devel] [PATCH 5/5] vmware-vga: use vmsvga_verify_rect in vmsvga_fill_rect Gerd Hoffmann

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