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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 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 3E5ADC433DF for ; Fri, 22 May 2020 13:13:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1CCD920723 for ; Fri, 22 May 2020 13:13:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729763AbgEVNNL (ORCPT ); Fri, 22 May 2020 09:13:11 -0400 Received: from helcar.hmeau.com ([216.24.177.18]:39262 "EHLO fornost.hmeau.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729334AbgEVNNL (ORCPT ); Fri, 22 May 2020 09:13:11 -0400 Received: from gwarestrin.arnor.me.apana.org.au ([192.168.0.7]) by fornost.hmeau.com with smtp (Exim 4.92 #5 (Debian)) id 1jc7Tj-0007Pz-B1; Fri, 22 May 2020 23:12:48 +1000 Received: by gwarestrin.arnor.me.apana.org.au (sSMTP sendmail emulation); Fri, 22 May 2020 23:12:47 +1000 Date: Fri, 22 May 2020 23:12:47 +1000 From: Herbert Xu To: Tero Kristo Cc: davem@davemloft.net, linux-crypto@vger.kernel.org, linux-omap@vger.kernel.org, Tejun Heo Subject: Re: [PATCHv2 3/7] crypto: omap-crypto: fix userspace copied buffer access Message-ID: <20200522131247.GA27255@gondor.apana.org.au> References: <20200511111913.26541-1-t-kristo@ti.com> <20200511111913.26541-4-t-kristo@ti.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200511111913.26541-4-t-kristo@ti.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-omap-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-omap@vger.kernel.org On Mon, May 11, 2020 at 02:19:09PM +0300, Tero Kristo wrote: > In case buffers are copied from userspace, directly accessing the page > will most likely fail because it hasn't been mapped into the kernel > memory space. Fix the issue by forcing a kmap / kunmap within the > cleanup functionality. > > Signed-off-by: Tero Kristo > --- > drivers/crypto/omap-crypto.c | 9 +++++++-- > 1 file changed, 7 insertions(+), 2 deletions(-) > > diff --git a/drivers/crypto/omap-crypto.c b/drivers/crypto/omap-crypto.c > index cc88b7362bc2..31bdb1d76d11 100644 > --- a/drivers/crypto/omap-crypto.c > +++ b/drivers/crypto/omap-crypto.c > @@ -178,11 +178,16 @@ static void omap_crypto_copy_data(struct scatterlist *src, > amt = min(src->length - srco, dst->length - dsto); > amt = min(len, amt); > > - srcb = sg_virt(src) + srco; > - dstb = sg_virt(dst) + dsto; > + srcb = kmap_atomic(sg_page(src)) + srco + src->offset; > + dstb = kmap_atomic(sg_page(dst)) + dsto + dst->offset; > > memcpy(dstb, srcb, amt); > > + flush_dcache_page(sg_page(dst)); You need to check !PageSlab as it's illegal to call it on a kernel page. Also you should be using flush_kernel_dcache_page. scatterwalk uses flush_dcache_page only because when it was created the other function didn't exist. Would it be possible to use the sg_miter interface to do the copy? In fact your function could possibly be added to lib/scatterlist.c as it seems to be quite generic. Thanks, -- Email: Herbert Xu Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt