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=-4.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 69F7EC433E4 for ; Wed, 29 Jul 2020 00:36:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5106620672 for ; Wed, 29 Jul 2020 00:36:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730891AbgG2Agd (ORCPT ); Tue, 28 Jul 2020 20:36:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44982 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730507AbgG2Agc (ORCPT ); Tue, 28 Jul 2020 20:36:32 -0400 Received: from shards.monkeyblade.net (shards.monkeyblade.net [IPv6:2620:137:e000::1:9]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CCB12C061794; Tue, 28 Jul 2020 17:36:32 -0700 (PDT) Received: from localhost (unknown [IPv6:2601:601:9f00:477::3d5]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) (Authenticated sender: davem-davemloft) by shards.monkeyblade.net (Postfix) with ESMTPSA id CAF50128D3F8B; Tue, 28 Jul 2020 17:19:44 -0700 (PDT) Date: Tue, 28 Jul 2020 17:36:29 -0700 (PDT) Message-Id: <20200728.173629.741539582090080322.davem@davemloft.net> To: bkkarthik@pesu.pes.edu Cc: steffen.klassert@secunet.com, herbert@gondor.apana.org.au, kuznet@ms2.inr.ac.ru, yoshfuji@linux-ipv6.org, kuba@kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, gregkh@linuxfoundation.org, skhan@linuxfoundation.org, linux-kernel-mentees@lists.linuxfoundation.org Subject: Re: [PATCH v2] net: ipv6: fix use-after-free Read in __xfrm6_tunnel_spi_lookup From: David Miller In-Reply-To: <20200726030855.q6dfjekazfzl5usw@pesu.pes.edu> References: <20200726030855.q6dfjekazfzl5usw@pesu.pes.edu> X-Mailer: Mew version 6.8 on Emacs 26.3 Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.12 (shards.monkeyblade.net [149.20.54.216]); Tue, 28 Jul 2020 17:19:45 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: B K Karthik Date: Sun, 26 Jul 2020 08:38:55 +0530 > @@ -103,10 +103,10 @@ static int __xfrm6_tunnel_spi_check(struct net *net, u32 spi) > { > struct xfrm6_tunnel_net *xfrm6_tn = xfrm6_tunnel_pernet(net); > struct xfrm6_tunnel_spi *x6spi; > - int index = xfrm6_tunnel_spi_hash_byspi(spi); > + int index = xfrm6_tunnel_spi_hash_byaddr((const xfrm_address_t *)spi); We can cast this a thousand times to make the compiler quiet, but the fact is that this function does not expect an integer SPI as an argument. It expects a protocol address. Please stop forcing this fix, I fear you don't understand how this code works. Come back to us when you do. Thank you.