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=-2.2 required=3.0 tests=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 8D709C2BA19 for ; Thu, 16 Apr 2020 02:26:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6FBD620936 for ; Thu, 16 Apr 2020 02:26:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731975AbgDPCZz (ORCPT ); Wed, 15 Apr 2020 22:25:55 -0400 Received: from helcar.hmeau.com ([216.24.177.18]:39942 "EHLO fornost.hmeau.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731031AbgDPCZv (ORCPT ); Wed, 15 Apr 2020 22:25:51 -0400 Received: from gwarestrin.me.apana.org.au ([192.168.0.7] helo=gwarestrin.arnor.me.apana.org.au) by fornost.hmeau.com with smtp (Exim 4.89 #2 (Debian)) id 1jOuD8-0001xU-SK; Thu, 16 Apr 2020 12:25:04 +1000 Received: by gwarestrin.arnor.me.apana.org.au (sSMTP sendmail emulation); Thu, 16 Apr 2020 12:25:02 +1000 Date: Thu, 16 Apr 2020 12:25:02 +1000 From: Herbert Xu To: Eric Biggers Cc: syzbot , davem@davemloft.net, linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, syzkaller-bugs@googlegroups.com Subject: Re: crypto: api - Fix use-after-free and race in crypto_spawn_alg Message-ID: <20200416022502.GA18386@gondor.apana.org.au> References: <0000000000002656a605a2a34356@google.com> <20200410060942.GA4048@gondor.apana.org.au> <20200416021703.GD816@sol.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200416021703.GD816@sol.localdomain> 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 Wed, Apr 15, 2020 at 07:17:03PM -0700, Eric Biggers wrote: > > Wouldn't it be a bit simpler to set 'target = NULL', remove 'shoot', > and use 'if (target)' instead of 'if (shoot)'? Yes it is simpler but it's actually semantically different because the compiler doesn't know that spawn->alg cannot be NULL in this case. Thanks, -- Email: Herbert Xu Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt