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=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT 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 4766CC46461 for ; Mon, 30 Jul 2018 00:18:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F0C4B20893 for ; Mon, 30 Jul 2018 00:18:54 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F0C4B20893 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=codewreck.org 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 S1728735AbeG3Buj (ORCPT ); Sun, 29 Jul 2018 21:50:39 -0400 Received: from nautica.notk.org ([91.121.71.147]:44396 "EHLO nautica.notk.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728118AbeG3Bui (ORCPT ); Sun, 29 Jul 2018 21:50:38 -0400 Received: by nautica.notk.org (Postfix, from userid 1001) id 7FA92C009; Mon, 30 Jul 2018 02:18:15 +0200 (CEST) Date: Mon, 30 Jul 2018 02:18:00 +0200 From: Dominique Martinet To: Tomas Bortoli Cc: v9fs-developer@lists.sourceforge.net, syzkaller@googlegroups.com, davem@davemloft.net, linux-kernel@vger.kernel.org, netdev@vger.kernel.org Subject: Re: [V9fs-developer] [PATCH] 9p: fix Use-After-Free in p9_write_work() Message-ID: <20180730001800.GA5960@nautica> References: <20180729130248.29612-1-tomasbortoli@gmail.com> <20180729233336.GB28684@nautica> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20180729233336.GB28684@nautica> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Dominique Martinet wrote on Mon, Jul 30, 2018: > Basically, a more global view of the problem is a race between > p9_tag_lookup returning a p9_req_t and another thread freeing it. (just correcting myself here, p9_tag_lookup won't be enough for the write side, but similarily you'd just need to increment the refcount when you schedule work with it and decrement when the worker is done) -- Dominique