From patchwork Sat May 16 13:13:03 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: BALATON Zoltan X-Patchwork-Id: 1291897 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=eik.bme.hu Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 49PQxd4h8Tz9sTK for ; Sat, 16 May 2020 23:25:07 +1000 (AEST) Received: from localhost ([::1]:45154 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jZwoJ-00081o-4z for incoming@patchwork.ozlabs.org; Sat, 16 May 2020 09:25:03 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:53036) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jZwnz-0007uo-Me for qemu-devel@nongnu.org; Sat, 16 May 2020 09:24:43 -0400 Received: from zero.eik.bme.hu ([2001:738:2001:2001::2001]:16434) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jZwnv-0004Po-T3 for qemu-devel@nongnu.org; Sat, 16 May 2020 09:24:40 -0400 Received: from zero.eik.bme.hu (blah.eik.bme.hu [152.66.115.182]) by localhost (Postfix) with SMTP id 53578746333; Sat, 16 May 2020 15:23:52 +0200 (CEST) Received: by zero.eik.bme.hu (Postfix, from userid 432) id 39E9374594E; Sat, 16 May 2020 15:23:52 +0200 (CEST) From: BALATON Zoltan Subject: [PATCH] ati-vga: Do not allow unaligned access via index register Date: Sat, 16 May 2020 15:13:03 +0200 MIME-Version: 1.0 To: qemu-devel@nongnu.org Message-Id: <20200516132352.39E9374594E@zero.eik.bme.hu> X-Spam-Probability: 8% Received-SPF: pass client-ip=2001:738:2001:2001::2001; envelope-from=balaton@eik.bme.hu; helo=zero.eik.bme.hu X-detected-operating-system: by eggs.gnu.org: No matching host in p0f cache. That's all we know. X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_NONE=-0.0001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001 autolearn=_AUTOLEARN X-Spam_action: no action 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: Gerd Hoffmann Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" According to docs bits 1 and 0 of MM_INDEX are hard coded to 0 so unaligned access via this register should not be possible. This also fixes problems reported in bug #1878134. Signed-off-by: BALATON Zoltan Acked-by: Alexander Bulekov Tested-by: Alexander Bulekov --- hw/display/ati.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/hw/display/ati.c b/hw/display/ati.c index f4c4542751..2ee23173b2 100644 --- a/hw/display/ati.c +++ b/hw/display/ati.c @@ -531,7 +531,7 @@ static void ati_mm_write(void *opaque, hwaddr addr, } switch (addr) { case MM_INDEX: - s->regs.mm_index = data; + s->regs.mm_index = data & ~3; break; case MM_DATA ... MM_DATA + 3: /* indexed access to regs or memory */