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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8349AEB64DC for ; Tue, 27 Jun 2023 17:35:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229718AbjF0Rfy (ORCPT ); Tue, 27 Jun 2023 13:35:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53630 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230482AbjF0Rfv (ORCPT ); Tue, 27 Jun 2023 13:35:51 -0400 Received: from mail3-relais-sop.national.inria.fr (mail3-relais-sop.national.inria.fr [192.134.164.104]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 510E4269E; Tue, 27 Jun 2023 10:35:49 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=inria.fr; s=dc; h=date:from:to:cc:subject:in-reply-to:message-id: references:mime-version; bh=iIHKX23DruyWxNvBPEkGuI6LxtvA8lzHrP07ul+XeWg=; b=Ixk+uerCSeTIr9ry6BMbctwfqD/cZnATnAx+lIta14URQK6WCY5xHjGm o3KZXqW1gNajuttsDVa436Hys12QuNPP2txSbbx2HNdh9pIRN48Mulca3 yAySyKmwGTMzvh54rhJs1cScpvyPiplespvWI9GEO7/NX4JgVXoWk5zMN 0=; Authentication-Results: mail3-relais-sop.national.inria.fr; dkim=none (message not signed) header.i=none; spf=SoftFail smtp.mailfrom=julia.lawall@inria.fr; dmarc=fail (p=none dis=none) d=inria.fr X-IronPort-AV: E=Sophos;i="6.01,163,1684792800"; d="scan'208";a="59972658" Received: from 231.85.89.92.rev.sfr.net (HELO hadrien) ([92.89.85.231]) by mail3-relais-sop.national.inria.fr with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 27 Jun 2023 19:35:47 +0200 Date: Tue, 27 Jun 2023 19:35:47 +0200 (CEST) From: Julia Lawall X-X-Sender: jll@hadrien To: Julia Lawall cc: Sakari Ailus , keescook@chromium.org, kernel-janitors@vger.kernel.org, Bingbu Cao , Tianshu Qiu , Mauro Carvalho Chehab , Greg Kroah-Hartman , linux-media@vger.kernel.org, linux-staging@lists.linux.dev, linux-kernel@vger.kernel.org Subject: Re: [PATCH 23/26] media: staging: imgu: use array_size In-Reply-To: <20230623211457.102544-24-Julia.Lawall@inria.fr> Message-ID: References: <20230623211457.102544-1-Julia.Lawall@inria.fr> <20230623211457.102544-24-Julia.Lawall@inria.fr> User-Agent: Alpine 2.22 (DEB 394 2020-01-19) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 23 Jun 2023, Julia Lawall wrote: > Use array_size to protect against multiplication overflows. > > The changes were done using the following Coccinelle semantic patch: > > // > @@ > expression E1, E2; > constant C1, C2; > identifier alloc = {vmalloc,vzalloc}; > @@ > > ( > alloc(C1 * C2,...) > | > alloc( > - (E1) * (E2) > + array_size(E1, E2) > ,...) > ) > // > > Signed-off-by: Julia Lawall > > --- > drivers/staging/media/ipu3/ipu3-mmu.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/staging/media/ipu3/ipu3-mmu.c b/drivers/staging/media/ipu3/ipu3-mmu.c > index cb9bf5fb29a5..9c4adb815c94 100644 > --- a/drivers/staging/media/ipu3/ipu3-mmu.c > +++ b/drivers/staging/media/ipu3/ipu3-mmu.c > @@ -464,7 +464,7 @@ struct imgu_mmu_info *imgu_mmu_init(struct device *parent, void __iomem *base) > * Allocate the array of L2PT CPU pointers, initialized to zero, > * which means the dummy L2PT allocated above. > */ > - mmu->l2pts = vzalloc(IPU3_PT_PTES * sizeof(*mmu->l2pts)); > + mmu->l2pts = vzalloc(array_size(IPU3_PT_PTES, sizeof(*mmu->l2pts))); > if (!mmu->l2pts) > goto fail_l2pt; I think that this patch can be dropped. Since it is a multiplcation of two constants, if there is an overflow, I guess the compiler would detect it? julia