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=-5.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no 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 77C7FC433DF for ; Tue, 4 Aug 2020 04:04:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7EBF1206F6 for ; Tue, 4 Aug 2020 04:04:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725807AbgHDEEy (ORCPT ); Tue, 4 Aug 2020 00:04:54 -0400 Received: from helcar.hmeau.com ([216.24.177.18]:54606 "EHLO fornost.hmeau.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725300AbgHDEEy (ORCPT ); Tue, 4 Aug 2020 00:04:54 -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 1k2oBY-0007a8-9k; Tue, 04 Aug 2020 14:04:21 +1000 Received: by gwarestrin.arnor.me.apana.org.au (sSMTP sendmail emulation); Tue, 04 Aug 2020 14:04:20 +1000 Date: Tue, 4 Aug 2020 14:04:20 +1000 From: Herbert Xu To: Liwei Song Cc: Tom Lendacky , Gary Hook , David , linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] crypto: ccp - zero the cmd data after use it Message-ID: <20200804040420.GA10850@gondor.apana.org.au> References: <20200803075858.3561-1-liwei.song@windriver.com> <20200803125242.GA7689@gondor.apana.org.au> <87ae939b-4983-4e96-cc3d-1aa1d1b3d3ae@windriver.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87ae939b-4983-4e96-cc3d-1aa1d1b3d3ae@windriver.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-crypto-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org On Tue, Aug 04, 2020 at 11:51:47AM +0800, Liwei Song wrote: > > On 8/3/20 20:52, Herbert Xu wrote: > > On Mon, Aug 03, 2020 at 03:58:58PM +0800, Liwei Song wrote: > >> exist the following assignment in ccp(ignore the force > >> convert of the struct) by list_del in ccp_dequeue_cmd(): > >> req->__ctx->cmd->entry->next = LIST_POISON1; > >> > >> after use the req, kzfree(req) can not zero the entry > >> entry->next = LIST_POISON1 of the ccp_cmd(cmd) struct > >> when this address available as slub freelist pointer, this will cause > >> the following "general protection fault" error if some process meet > >> this LIST_POISON1 value address when request memory: > > > > Your description makes no sense. Please rewrite it and explain > > the problem properly. > > The problem here is that the entry of struct ccp_cmd is not zeroed after we use it, > If the other process got this address by kmalloc(), this illegal value "LIST_POISON1" > will cause "general protection fault" error. If that's the case surely the other process should be zeroing the memory? Your explanation still makes no sense. Thanks, -- Email: Herbert Xu Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt