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=-2.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_MUTT autolearn=unavailable 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 393AFC31E5E for ; Tue, 18 Jun 2019 14:53:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1074B20873 for ; Tue, 18 Jun 2019 14:53:18 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="pbyrk4o9" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729272AbfFROxP (ORCPT ); Tue, 18 Jun 2019 10:53:15 -0400 Received: from mail-qk1-f181.google.com ([209.85.222.181]:41351 "EHLO mail-qk1-f181.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727105AbfFROxO (ORCPT ); Tue, 18 Jun 2019 10:53:14 -0400 Received: by mail-qk1-f181.google.com with SMTP id c11so8729933qkk.8; Tue, 18 Jun 2019 07:53:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=0q+lDhwoSzLW/vGLXgPFr1bRPZrHxwKku/Yc4H2Wc70=; b=pbyrk4o9ZgXacJhZgx6ZYLbBTYI/GQmPImCY/q9Giq0Tv3W9d861V0Cu2qiomhVjbb JfpKce9xOkyJmthgWXQjAwCXlKibJ5VLVRIU4eFIt7OqNgca1DaMSFoD34o/td1Syr9n CvQ/r6HlXUTC/bR2TT9yqO3kDRFBGtCp91/1D0VZRg890YIWI2c9sjMTh/x031HnckIx 58OfV5wltHCi0jOTJdvmbzOOQ12+wrcF3nV9hplOmrmIeetxeqLUOglQ6EaSITQ/wrPe 4K6/EbZUzA+gpOU9zJcsN9ZELmhWTop2AsdoGc5H0k/v6H/MjFdYbImuH5ifP1Ilzy/P 5czQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=0q+lDhwoSzLW/vGLXgPFr1bRPZrHxwKku/Yc4H2Wc70=; b=OpqDbhAdkKG5rVnRtYBqFUQBOyk6eqo5GHBEwhoQXiCNsp4pZUDguM07qVFwbTUg8c IV5XTk7WGDJwoRKxPZy26jyBafXZJbNpD5b+2P810Dk5hV6mf7ctphmLuyg9rmhylQeF tG76MFzbKqCN10LQlnBniZFn1/evCxl+j564lpvkESkEWWbOKxwiN0kd/iigUMKqoQjS ZfDf6E6wTvO3purhh79f40VzN9ycH6dStFLS8qYWwfu61KZhmXk1rKRuOmmbl0YkyIpj VSwu0982HvK2JlmZNHnlXKWumC3viXuzRSupKijCCwQ+lGZGFTvDQ5KPphq4CX2/tozp d3IA== X-Gm-Message-State: APjAAAUSYeLoR7sEZ6vmjK8NGH74j1uPd0JaQOzFewmUooeAcfyCPyJY XrdUUiCX84tseffXc7lRQr8= X-Google-Smtp-Source: APXvYqwqkiOizVJT0BN9XC/wOoplesdna8o2HjjyGCz1flnMO5Yksw8V3lk+IYPg8hJf2jEL4hlwnw== X-Received: by 2002:ae9:eb96:: with SMTP id b144mr14015575qkg.321.1560869593227; Tue, 18 Jun 2019 07:53:13 -0700 (PDT) Received: from localhost.localdomain ([168.181.49.32]) by smtp.gmail.com with ESMTPSA id o22sm7976457qkk.50.2019.06.18.07.53.12 (version=TLS1_3 cipher=AEAD-AES256-GCM-SHA384 bits=256/256); Tue, 18 Jun 2019 07:53:12 -0700 (PDT) Received: by localhost.localdomain (Postfix, from userid 1000) id F2C2AC0FFC; Tue, 18 Jun 2019 11:53:09 -0300 (-03) Date: Tue, 18 Jun 2019 11:53:09 -0300 From: Marcelo Ricardo Leitner To: Hillf Danton Cc: syzbot , "davem@davemloft.net" , "linux-kernel@vger.kernel.org" , "linux-sctp@vger.kernel.org" , "lucien.xin@gmail.com" , "netdev@vger.kernel.org" , "nhorman@tuxdriver.com" , "syzkaller-bugs@googlegroups.com" , "vyasevich@gmail.com" Subject: Re: general protection fault in sctp_sched_prio_sched Message-ID: <20190618145309.GO3436@localhost.localdomain> References: <20190618144554.5016-1-hdanton@sina.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190618144554.5016-1-hdanton@sina.com> User-Agent: Mutt/1.11.4 (2019-03-13) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Tue, Jun 18, 2019 at 10:45:54PM +0800, Hillf Danton wrote: ... > > Anyway, with the patch above, after calling > > sctp_stream_init_ext() ->ext will be either completely valid, or it > > will not be present at all as it is seting ->ext to NULL if sid > > initialization ended up failing. > > > Correct with no doubt. > > I was wondering if it is likely for the ->ext, loaded with a valid slab, > to cause a gpf in sctp_sched_prio_sched() without your patch applied. > And if the failure to initialise sid could likely change the result. Thanks, I think I understand now. Well, without the patch, yes, as syzbot reported. Seems you're also worried if it can happen in other situations as well, and end up triggering the same gpf but on a different situation. I don't think so. It should be either initialized or not initialized. Half-initialized as it was, that's a pain. Marcelo