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=-7.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,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 678EAC04EBF for ; Tue, 4 Dec 2018 14:45:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1A7712082D for ; Tue, 4 Dec 2018 14:45:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=umn.edu header.i=@umn.edu header.b="POPCE9YA" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1A7712082D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=umn.edu 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 S1726632AbeLDOpE (ORCPT ); Tue, 4 Dec 2018 09:45:04 -0500 Received: from mta-p3.oit.umn.edu ([134.84.196.203]:41134 "EHLO mta-p3.oit.umn.edu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726309AbeLDOpE (ORCPT ); Tue, 4 Dec 2018 09:45:04 -0500 X-Greylist: delayed 566 seconds by postgrey-1.27 at vger.kernel.org; Tue, 04 Dec 2018 09:45:03 EST Received: from localhost (localhost [127.0.0.1]) by mta-p3.oit.umn.edu (Postfix) with ESMTP id 2E96B773 for ; Tue, 4 Dec 2018 14:35:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=umn.edu; h= content-type:content-type:subject:subject:message-id:date:date :from:from:in-reply-to:references:mime-version:received:received :received; s=20160920; t=1543934137; x=1545748538; bh=fxK91B2Yz0 Ck0tUzvkhSsKruWIrkhKWLdQ/YbD7u6S8=; b=POPCE9YAB1mQiBXhxCBNWXh8LP YCIPc9HXytDxXBc+RCfz84/Gr1vZBpb56msHvMxZQBbCTb1m30b3YsQldtz74pEt abHpGU0/SJKQFn3+ibaIDiJvYYbEEf+PRH7pf/dUigp7rh7VFE0cUwRdeGRrNAlA GbHxFZ3RPDcbhUhZk/TaYI5ztLMkJf4fYlCsvxJ5rwuPePOmeukYjSS1J7UQfD9G XgpwLpY06gjtCjZo7Y7GDEpSIOhZ4UC5m980nB+rQv+4k+UGxeT1e8gCSvGh755k bLXEA/2q1KXf0FVw3eC/HOUOruBxpi4OzzWS8IuzC0mh90uC0IvQepwoUPRA== X-Virus-Scanned: amavisd-new at umn.edu Received: from mta-p3.oit.umn.edu ([127.0.0.1]) by localhost (mta-p3.oit.umn.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 51TIRMq6Pz9G for ; Tue, 4 Dec 2018 08:35:37 -0600 (CST) Received: from mail-it1-f177.google.com (mail-it1-f177.google.com [209.85.166.177]) (using TLSv1 with cipher AES128-SHA (128/128 bits)) (No client certificate requested) (Authenticated sender: wang6495) by mta-p3.oit.umn.edu (Postfix) with ESMTPSA id 00FC679F for ; Tue, 4 Dec 2018 08:35:37 -0600 (CST) Received: by mail-it1-f177.google.com with SMTP id i145so15626488ita.4 for ; Tue, 04 Dec 2018 06:35:36 -0800 (PST) X-Gm-Message-State: AA+aEWZAz2+hfaO7oklOUT9SySXQoVDz4BYWRha2DDcgEsXuU9G8lEXW GxgAEKpdb+a8zmSUPt/mW/Sey7edhUF8WsS1NMc= X-Google-Smtp-Source: AFSGD/Uf0AhRCIX7vaZpq5y3wONR4kt4eLYppjYgqID1wTkLrASx/XEi7fRAWFRFCQ5yyn+c4TarGL+CTrZIKDntjMc= X-Received: by 2002:a24:97c3:: with SMTP id k186mr12598454ite.125.1543934136720; Tue, 04 Dec 2018 06:35:36 -0800 (PST) MIME-Version: 1.0 References: <1539891966-8017-1-git-send-email-wang6495@umn.edu> <1541384613.28670.5.camel@intel.com> In-Reply-To: <1541384613.28670.5.camel@intel.com> From: Wenwen Wang Date: Tue, 4 Dec 2018 08:35:00 -0600 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH] misc: mic: fix a DMA pool free failure To: sudeep.dutt@intel.com Cc: Kangjie Lu , ashutosh.dixit@intel.com, Arnd Bergmann , Greg Kroah-Hartman , open list , Wenwen Wang 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 Sun, Nov 4, 2018 at 8:05 PM Sudeep Dutt wrote: > > On Thu, 2018-10-18 at 14:46 -0500, Wenwen Wang wrote: > > In _scif_prog_signal(), a DMA pool is allocated if the MIC Coprocessor is > > not X100, i.e., the boolean variable 'x100' is false. This DMA pool will be > > freed eventually through the callback function scif_prog_signal_cb() with > > the parameter of 'status', which actually points to the start of DMA pool. > > Specifically, in scif_prog_signal_cb(), the 'ep' field and the > > 'src_dma_addr' field of 'status' are used to free the DMA pool by invoking > > dma_pool_free(). Given that 'status' points to the start address of the DMA > > pool, both 'status->ep' and 'status->src_dma_addr' are in the DMA pool. And > > so, the device has the permission to access them. Even worse, a malicious > > device can modify them. As a result, dma_pool_free() will not succeed. > > > > To avoid the above issue, this patch introduces a new data structure, i.e., > > scif_cb_arg, to store the arguments required by the call back function. A > > variable 'cb_arg' is allocated in _scif_prog_signal() to pass the > > arguments. 'cb_arg' will be freed after dma_pool_free() in > > scif_prog_signal_cb(). > > > > Signed-off-by: Wenwen Wang > > --- > > drivers/misc/mic/scif/scif_fence.c | 17 +++++++++++++---- > > drivers/misc/mic/scif/scif_rma.h | 14 ++++++++++++++ > > 2 files changed, 27 insertions(+), 4 deletions(-) > > > > diff --git a/drivers/misc/mic/scif/scif_fence.c b/drivers/misc/mic/scif/scif_fence.c > > index cac3bcc..30f7d9b 100644 > > --- a/drivers/misc/mic/scif/scif_fence.c > > +++ b/drivers/misc/mic/scif/scif_fence.c > > @@ -195,10 +195,11 @@ static inline void *scif_get_local_va(off_t off, struct scif_window *window) > > > > static void scif_prog_signal_cb(void *arg) > > { > > - struct scif_status *status = arg; > > + struct scif_cb_arg *cb_arg = arg; > > > > - dma_pool_free(status->ep->remote_dev->signal_pool, status, > > - status->src_dma_addr); > > + dma_pool_free(cb_arg->ep->remote_dev->signal_pool, cb_arg->status, > > + cb_arg->src_dma_addr); > > + kfree(cb_arg); > > } > > > > static int _scif_prog_signal(scif_epd_t epd, dma_addr_t dst, u64 val) > > @@ -209,6 +210,7 @@ static int _scif_prog_signal(scif_epd_t epd, dma_addr_t dst, u64 val) > > bool x100 = !is_dma_copy_aligned(chan->device, 1, 1, 1); > > struct dma_async_tx_descriptor *tx; > > struct scif_status *status = NULL; > > + struct scif_cb_arg *cb_arg = NULL; > > dma_addr_t src; > > dma_cookie_t cookie; > > int err; > > @@ -257,8 +259,15 @@ static int _scif_prog_signal(scif_epd_t epd, dma_addr_t dst, u64 val) > > goto dma_fail; > > } > > if (!x100) { > > + err = -ENOMEM; > > Should err be set to -ENOMEM only if the cb_arg allocation fails? > > > + cb_arg = kmalloc(sizeof(*cb_arg), GFP_KERNEL); > > + if (!cb_arg) > > + goto dma_fail; > > + cb_arg->src_dma_addr = src; > > + cb_arg->status = status; > > + cb_arg->ep = ep; > > tx->callback = scif_prog_signal_cb; > > - tx->callback_param = status; > > + tx->callback_param = cb_arg; > > } > > cb_arg should be freed if there is a dma_submit_error(..) below in the > dma_fail path. > > Wenwen, can you please fix these up and resend the patch? Sure, will fix the issues and resubmit the patch. Thanks! Wenwen