From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 79DCCC433F5 for ; Mon, 4 Oct 2021 21:36:51 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 223FC6120D for ; Mon, 4 Oct 2021 21:36:51 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 223FC6120D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ilande.co.uk Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=nongnu.org Received: from localhost ([::1]:49876 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mXVdi-000320-6F for qemu-devel@archiver.kernel.org; Mon, 04 Oct 2021 17:36:50 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:56790) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mXVNI-0001Po-BS for qemu-devel@nongnu.org; Mon, 04 Oct 2021 17:19:52 -0400 Received: from mail.ilande.co.uk ([2001:41c9:1:41f::167]:35842 helo=mail.default.ilande.bv.iomart.io) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mXVNH-00021U-1w for qemu-devel@nongnu.org; Mon, 04 Oct 2021 17:19:52 -0400 Received: from [2a00:23c4:8b9d:4100:5d98:71b5:90ca:dad1] (helo=kentang.home) by mail.default.ilande.bv.iomart.io with esmtpsa (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1mXVN2-0008kv-4Y; Mon, 04 Oct 2021 22:19:40 +0100 From: Mark Cave-Ayland To: qemu-devel@nongnu.org, laurent@vivier.eu Date: Mon, 4 Oct 2021 22:19:19 +0100 Message-Id: <20211004211928.15803-4-mark.cave-ayland@ilande.co.uk> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20211004211928.15803-1-mark.cave-ayland@ilande.co.uk> References: <20211004211928.15803-1-mark.cave-ayland@ilande.co.uk> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-SA-Exim-Connect-IP: 2a00:23c4:8b9d:4100:5d98:71b5:90ca:dad1 X-SA-Exim-Mail-From: mark.cave-ayland@ilande.co.uk Subject: [PATCH v2 03/12] macfb: fix overflow of color_palette array X-SA-Exim-Version: 4.2.1 (built Wed, 08 May 2019 21:11:16 +0000) X-SA-Exim-Scanned: Yes (on mail.default.ilande.bv.iomart.io) Received-SPF: pass client-ip=2001:41c9:1:41f::167; envelope-from=mark.cave-ayland@ilande.co.uk; helo=mail.default.ilande.bv.iomart.io 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, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no 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: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" The palette_current index counter has a maximum size of 256 * 3 to cover a full color palette of 256 RGB entries. Linux assumes that the palette_current index wraps back around to zero after writing 256 RGB entries so ensure that palette_current is reset at this point to prevent data corruption within MacfbState. Signed-off-by: Mark Cave-Ayland --- hw/display/macfb.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/hw/display/macfb.c b/hw/display/macfb.c index b363bab889..39dab49026 100644 --- a/hw/display/macfb.c +++ b/hw/display/macfb.c @@ -303,7 +303,9 @@ static void macfb_ctrl_write(void *opaque, s->palette_current = 0; break; case DAFB_LUT: - s->color_palette[s->palette_current++] = val; + s->color_palette[s->palette_current] = val; + s->palette_current = (s->palette_current + 1) % + ARRAY_SIZE(s->color_palette); if (s->palette_current % 3) { macfb_invalidate_display(s); } -- 2.20.1