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From: Gerd Hoffmann <kraxel@redhat.com>
Date: Mon, 13 Mar 2017 14:55:07 +0100
In-Reply-To: <20170313131029.14044-1-hangaohuai@huawei.com>
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Subject: Re: [Qemu-devel] [PATCH] fix :cirrus_vga fix OOB read case qemu
 Segmentation fault
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To: hangaohuai <hangaohuai@huawei.com>
Cc: qemu-devel@nongnu.org, fangying1@huawei.com, arei.gonglei@huawei.com

> @@ -97,6 +97,11 @@ glue(glue(cirrus_bitblt_rop_fwd_transp_, ROP_NAME),_8)=
(CirrusVGAState *s,
>      uint8_t p;
>      dstpitch -=3D bltwidth;
>      srcpitch -=3D bltwidth;
> +
> +    if (dstpitch < 0 || srcpitch < 0) {
> +        return;
> +    }

Shouldn't that be ...

    if (bltheight > 1 && (dstpitch < 0 || srcpitch < 0)) {


... matching the check of the non-transparent version a few lines up in
the same source file?

cheers,
  Gerd