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=ham 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 43B04C43603 for ; Thu, 19 Dec 2019 18:46:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 18EDC24672 for ; Thu, 19 Dec 2019 18:46:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1576781171; bh=ukK3tZ03T2ojLubsfuqKbVnsJ0LNvG8yLEX+MReaYbk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=z0pcRDCnNA0o763XYlfNdoprg3CBM5VVObPTGfvg0BlU3Fpa1KZny4z5mFTRm+yEq fXhwTXFUdb12jrlxvq/cAGPqiJDRXXz9FylrCt+TqEX+U6gsUwuVq1YmYuDJrB5CjD c9tOoH3YidoqQffhdxyakLxjG4KqTnlxqrgYA9ak= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729299AbfLSSqJ (ORCPT ); Thu, 19 Dec 2019 13:46:09 -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: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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;