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=-7.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED 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 DD2DBECE560 for ; Mon, 17 Sep 2018 13:00:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6FE352147A for ; Mon, 17 Sep 2018 13:00:08 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="er5FRZhz" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6FE352147A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728311AbeIQS1T (ORCPT ); Mon, 17 Sep 2018 14:27:19 -0400 Received: from mail.kernel.org ([198.145.29.99]:41860 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726889AbeIQS1T (ORCPT ); Mon, 17 Sep 2018 14:27:19 -0400 Received: from mail-wr1-f42.google.com (mail-wr1-f42.google.com [209.85.221.42]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 397ED2147A; Mon, 17 Sep 2018 13:00:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1537189205; bh=cyOd9xRfXngf+LId+Y+OLkh0sSSHZaCGH6RHI29NQEw=; h=References:In-Reply-To:From:Date:Subject:To:Cc:From; b=er5FRZhzP6FR8V371SPRGfXvGXqN4kUTxMvV+8DxkH1uMiUlHFNT+rqB8Gbpf1+EX ExmUapqtfVHLD//m1WHXql/abck8Ais3aynpKJnkRXbkQVCZxU9fKDqLycFilM3mnN 3swTD1I97XpN3BvzNeE0Kk/oEyM71zhp9L97j1Qw= Received: by mail-wr1-f42.google.com with SMTP id a108-v6so17190949wrc.13; Mon, 17 Sep 2018 06:00:05 -0700 (PDT) X-Gm-Message-State: APzg51DGUWBRuv6UunA1X0nvFOSo5goFEejLyjnrl6XQkQNQRH+3lVUY cmcrz3oiWHySz5OX0GhcmY2T4rmwym0tFoTfIrE= X-Google-Smtp-Source: ANB0VdZU80jpSazpFaB9P5zHWGxujTZpyF2Fr8jtcOpD5vzkWk4LexJG1AIkkBACYheBk6wru6lq4qPCJFDt61opx+E= X-Received: by 2002:a05:6000:10d0:: with SMTP id b16mr18996315wrx.226.1537189203625; Mon, 17 Sep 2018 06:00:03 -0700 (PDT) MIME-Version: 1.0 References: <1536825522-6027-1-git-send-email-c.manszewski@samsung.com> <20180913075857eucas1p2cbccf3cd452a23eb46a234acb37b3a44~T5q8CpLOD2420024200eucas1p24@eucas1p2.samsung.com> In-Reply-To: <20180913075857eucas1p2cbccf3cd452a23eb46a234acb37b3a44~T5q8CpLOD2420024200eucas1p24@eucas1p2.samsung.com> From: Krzysztof Kozlowski Date: Mon, 17 Sep 2018 14:59:52 +0200 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH 1/4] crypto: s5p-sss: Fix race in error handling To: c.manszewski@samsung.com Cc: linux-crypto@vger.kernel.org, vz@mleia.com, k.konieczny@partner.samsung.com, herbert@gondor.apana.org.au, davem@davemloft.net, "linux-samsung-soc@vger.kernel.org" , linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 13 Sep 2018 at 09:59, Christoph Manszewski wrote: > > Remove a race condition introduced by error path in functions: > s5p_aes_interrupt and s5p_aes_crypt_start. Setting the busy field of > struct s5p_aes_dev to false made it possible for s5p_tasklet_cb to > change the req field, before s5p_aes_complete was called. Nice catch. Indeed the code looks racy. > > Change the first parameter of s5p_aes_complete to struct > ablkcipher_request. Before spin_unlock, make a copy of the currently > handled request, to ensure s5p_aes_complete function call with the > correct request. > > Signed-off-by: Christoph Manszewski > --- > drivers/crypto/s5p-sss.c | 13 ++++++++----- > 1 file changed, 8 insertions(+), 5 deletions(-) > > diff --git a/drivers/crypto/s5p-sss.c b/drivers/crypto/s5p-sss.c > index faa282074e5a..0cf3f12d8f74 100644 > --- a/drivers/crypto/s5p-sss.c > +++ b/drivers/crypto/s5p-sss.c > @@ -475,9 +475,9 @@ static void s5p_sg_done(struct s5p_aes_dev *dev) > } > > /* Calls the completion. Cannot be called with dev->lock hold. */ > -static void s5p_aes_complete(struct s5p_aes_dev *dev, int err) > +static void s5p_aes_complete(struct ablkcipher_request *req, int err) > { > - dev->req->base.complete(&dev->req->base, err); > + req->base.complete(&req->base, err); > } > > static void s5p_unset_outdata(struct s5p_aes_dev *dev) > @@ -655,6 +655,7 @@ static irqreturn_t s5p_aes_interrupt(int irq, void *dev_id) > { > struct platform_device *pdev = dev_id; > struct s5p_aes_dev *dev = platform_get_drvdata(pdev); > + struct ablkcipher_request *req; > int err_dma_tx = 0; > int err_dma_rx = 0; > int err_dma_hx = 0; > @@ -725,9 +726,10 @@ static irqreturn_t s5p_aes_interrupt(int irq, void *dev_id) > if (err_dma_hx == 1) > s5p_set_dma_hashdata(dev, dev->hash_sg_iter); > > + req = dev->req; In this path it should not be needed, so just s5p_aes_complete(dev->req)? At this point dev->busy is true so s5p_aes_handle_req() will exit before starting new tasklet. Also the interrupt is an effect of finishing work by device scheduled in last tasklet... so obviously no tasklet should be running. > spin_unlock_irqrestore(&dev->lock, flags); > > - s5p_aes_complete(dev, 0); > + s5p_aes_complete(req, 0); > /* Device is still busy */ > tasklet_schedule(&dev->tasklet); > } else { > @@ -755,8 +757,9 @@ static irqreturn_t s5p_aes_interrupt(int irq, void *dev_id) > if (err_dma_hx == 1) > s5p_set_dma_hashdata(dev, dev->hash_sg_iter); > > + req = dev->req; Please put it before new line (so there will be new line before unlock). Logically it should not be separated from other commands in error path. Best regards, Krzysztof