From nobody Sun May 19 04:34:56 2024 Delivered-To: importer@patchew.org Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org ARC-Seal: i=1; a=rsa-sha256; t=1586205715; cv=none; d=zohomail.com; s=zohoarc; b=inKC/XFdVC8eoqD9HDUy/JX+bxDPwuAm5ccu+iPAl8v67hKBYp9fQkO91N7YoPNGWg7OePUXTnnRIlkkrUHxO5qL6UJS7hNvB/v2vwl3QR4+j99GskAl1KkcftKs8IPnQeOMqArjTE52QwgsKzYJni64+C8eAkaF+1rC8UPQe/0= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1586205715; h=Content-Type:Content-Transfer-Encoding:Cc:Date:From:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:MIME-Version:Message-ID:Sender:Subject:To; bh=a0Zygc2Z3A7H4HKdfzLt32XO+BLS5vEJqeIFYO/n4lo=; b=TXXK2dZCbmHN3OlY6cwtiE5rPg0KgG7wWVReDrCLPw/cRWpDgUTGSCXJHxC2pBQvPXEQRD/kCwHR5UqwfFnFdNzinPVd5Kl189ZmN7zMHniRfxwYcmpCqWVmkfXGTvxm9biddei234mBAeUVcVSvSmFCJmsFTxk2WuRGjGA/H7w= ARC-Authentication-Results: i=1; mx.zohomail.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1586205715363500.2804339263997; Mon, 6 Apr 2020 13:41:55 -0700 (PDT) Received: from localhost ([::1]:37940 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jLYZ8-00015S-4X for importer@patchew.org; Mon, 06 Apr 2020 16:41:54 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:60934) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jLYY1-0008Pu-II for qemu-devel@nongnu.org; Mon, 06 Apr 2020 16:40:46 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1jLYXz-0006Dn-NW for qemu-devel@nongnu.org; Mon, 06 Apr 2020 16:40:44 -0400 Received: from zero.eik.bme.hu ([152.66.115.2]:57373) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1jLYXv-00061V-CX for qemu-devel@nongnu.org; Mon, 06 Apr 2020 16:40:43 -0400 Received: from zero.eik.bme.hu (blah.eik.bme.hu [152.66.115.182]) by localhost (Postfix) with SMTP id 3B141747DF7; Mon, 6 Apr 2020 22:40:29 +0200 (CEST) Received: by zero.eik.bme.hu (Postfix, from userid 432) id 19559747D5D; Mon, 6 Apr 2020 22:40:29 +0200 (CEST) From: BALATON Zoltan Subject: [PATCH] ati-vga: Fix checks in ati_2d_blt() to avoid crash Date: Mon, 06 Apr 2020 22:34:26 +0200 MIME-Version: 1.0 To: qemu-devel@nongnu.org Message-Id: <20200406204029.19559747D5D@zero.eik.bme.hu> Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: FreeBSD 9.x [fuzzy] X-Received-From: 152.66.115.2 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: mcascell@redhat.com, Gerd Hoffmann Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" Content-Type: text/plain; charset="utf-8" In some corner cases (that never happen during normal operation but a malicious guest could program wrong values) pixman functions were called with parameters that result in a crash. Fix this and add more checks to disallow such cases. Reported-by: Ziming Zhang Signed-off-by: BALATON Zoltan --- hw/display/ati_2d.c | 37 ++++++++++++++++++++++++++----------- 1 file changed, 26 insertions(+), 11 deletions(-) diff --git a/hw/display/ati_2d.c b/hw/display/ati_2d.c index 42e82311eb..23a8ae0cd8 100644 --- a/hw/display/ati_2d.c +++ b/hw/display/ati_2d.c @@ -53,12 +53,20 @@ void ati_2d_blt(ATIVGAState *s) s->vga.vbe_start_addr, surface_data(ds), surface_stride(ds), surface_bits_per_pixel(ds), (s->regs.dp_mix & GMC_ROP3_MASK) >> 16); - int dst_x =3D (s->regs.dp_cntl & DST_X_LEFT_TO_RIGHT ? - s->regs.dst_x : s->regs.dst_x + 1 - s->regs.dst_width); - int dst_y =3D (s->regs.dp_cntl & DST_Y_TOP_TO_BOTTOM ? - s->regs.dst_y : s->regs.dst_y + 1 - s->regs.dst_height); + unsigned dst_x =3D (s->regs.dp_cntl & DST_X_LEFT_TO_RIGHT ? + s->regs.dst_x : s->regs.dst_x + 1 - s->regs.dst_widt= h); + unsigned dst_y =3D (s->regs.dp_cntl & DST_Y_TOP_TO_BOTTOM ? + s->regs.dst_y : s->regs.dst_y + 1 - s->regs.dst_heig= ht); int bpp =3D ati_bpp_from_datatype(s); + if (!bpp) { + qemu_log_mask(LOG_GUEST_ERROR, "Invalid bpp\n"); + return; + } int dst_stride =3D DEFAULT_CNTL ? s->regs.dst_pitch : s->regs.default_= pitch; + if (!dst_stride) { + qemu_log_mask(LOG_GUEST_ERROR, "Zero dest pitch\n"); + return; + } uint8_t *dst_bits =3D s->vga.vram_ptr + (DEFAULT_CNTL ? s->regs.dst_offset : s->regs.default_offset); =20 @@ -82,12 +90,16 @@ void ati_2d_blt(ATIVGAState *s) switch (s->regs.dp_mix & GMC_ROP3_MASK) { case ROP3_SRCCOPY: { - int src_x =3D (s->regs.dp_cntl & DST_X_LEFT_TO_RIGHT ? - s->regs.src_x : s->regs.src_x + 1 - s->regs.dst_width= ); - int src_y =3D (s->regs.dp_cntl & DST_Y_TOP_TO_BOTTOM ? - s->regs.src_y : s->regs.src_y + 1 - s->regs.dst_heigh= t); + unsigned src_x =3D (s->regs.dp_cntl & DST_X_LEFT_TO_RIGHT ? + s->regs.src_x : s->regs.src_x + 1 - s->regs.dst_wid= th); + unsigned src_y =3D (s->regs.dp_cntl & DST_Y_TOP_TO_BOTTOM ? + s->regs.src_y : s->regs.src_y + 1 - s->regs.dst_hei= ght); int src_stride =3D DEFAULT_CNTL ? s->regs.src_pitch : s->regs.default_pitch; + if (!src_stride) { + qemu_log_mask(LOG_GUEST_ERROR, "Zero source pitch\n"); + return; + } uint8_t *src_bits =3D s->vga.vram_ptr + (DEFAULT_CNTL ? s->regs.src_offset : s->regs.default_offset); =20 @@ -137,8 +149,10 @@ void ati_2d_blt(ATIVGAState *s) dst_y * surface_stride(ds), s->regs.dst_height * surface_stride(ds= )); } - s->regs.dst_x +=3D s->regs.dst_width; - s->regs.dst_y +=3D s->regs.dst_height; + s->regs.dst_x =3D (s->regs.dp_cntl & DST_X_LEFT_TO_RIGHT ? + dst_x + s->regs.dst_width : dst_x); + s->regs.dst_y =3D (s->regs.dp_cntl & DST_Y_TOP_TO_BOTTOM ? + dst_y + s->regs.dst_height : dst_y); break; } case ROP3_PATCOPY: @@ -179,7 +193,8 @@ void ati_2d_blt(ATIVGAState *s) dst_y * surface_stride(ds), s->regs.dst_height * surface_stride(ds= )); } - s->regs.dst_y +=3D s->regs.dst_height; + s->regs.dst_y =3D (s->regs.dp_cntl & DST_Y_TOP_TO_BOTTOM ? + dst_y + s->regs.dst_height : dst_y); break; } default: --=20 2.21.1