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
>
>
>
next prev parent 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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