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 X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 992BCC43603 for ; Thu, 19 Dec 2019 19:05:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 63E4F222C2 for ; Thu, 19 Dec 2019 19:05:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1576782313; bh=ukK3tZ03T2ojLubsfuqKbVnsJ0LNvG8yLEX+MReaYbk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=1i2maixQwJLr8vwRHnVBTX37WV1nLfjMSQgS1AlMi2ylKkm+NLZg7ToRLhFh4QJhT x/gqGONZuEOH2a+cYAF+k36yviRG8jJUaUeXjvBwi6A3mtj4KLXCnAx9alsXlRxTfn 26LbItB6iFW8YpQ1WU96ErBA08YK+EN395gsL0mA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729289AbfLSSqI (ORCPT ); Thu, 19 Dec 2019 13:46:08 -0500 Received: from mail.kernel.org ([198.145.29.99]:38718 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729287AbfLSSqI (ORCPT ); Thu, 19 Dec 2019 13:46:08 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 2D74C24679; Thu, 19 Dec 2019 18:46:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1576781167; bh=ukK3tZ03T2ojLubsfuqKbVnsJ0LNvG8yLEX+MReaYbk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=yK41FEhz4nKRO3f+vM7R9xTsiVvsVEIyJKRTxUQydM+H0B2imLYbWQAEeZlauMkjQ m13LiCqZdDtH7ygnhTuuTx9sb5F/FzEQk+KT3q7b599BTwiy5OxgtqgKru8aevbMYy 1QxwofepZNy/yNZJsO6e7ZGFzqvvm/l2eQHruUrw= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dan Carpenter , Chris Wilson Subject: [PATCH 4.9 083/199] drm/i810: Prevent underflow in ioctl Date: Thu, 19 Dec 2019 19:32:45 +0100 Message-Id: <20191219183219.549159529@linuxfoundation.org> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20191219183214.629503389@linuxfoundation.org> References: <20191219183214.629503389@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Dan Carpenter commit 4f69851fbaa26b155330be35ce8ac393e93e7442 upstream. The "used" variables here come from the user in the ioctl and it can be negative. It could result in an out of bounds write. Signed-off-by: Dan Carpenter Reviewed-by: Chris Wilson Signed-off-by: Chris Wilson Link: https://patchwork.freedesktop.org/patch/msgid/20191004102251.GC823@mwanda Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/i810/i810_dma.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/drivers/gpu/drm/i810/i810_dma.c +++ b/drivers/gpu/drm/i810/i810_dma.c @@ -723,7 +723,7 @@ static void i810_dma_dispatch_vertex(str if (nbox > I810_NR_SAREA_CLIPRECTS) nbox = I810_NR_SAREA_CLIPRECTS; - if (used > 4 * 1024) + if (used < 0 || used > 4 * 1024) used = 0; if (sarea_priv->dirty) @@ -1043,7 +1043,7 @@ static void i810_dma_dispatch_mc(struct if (u != I810_BUF_CLIENT) DRM_DEBUG("MC found buffer that isn't mine!\n"); - if (used > 4 * 1024) + if (used < 0 || used > 4 * 1024) used = 0; sarea_priv->dirty = 0x7f;