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=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 AA6C9C43381 for ; Thu, 14 Feb 2019 00:34:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 821F92083E for ; Thu, 14 Feb 2019 00:34:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726228AbfBNAe2 (ORCPT ); Wed, 13 Feb 2019 19:34:28 -0500 Received: from shards.monkeyblade.net ([23.128.96.9]:46676 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726130AbfBNAe2 (ORCPT ); Wed, 13 Feb 2019 19:34:28 -0500 Received: from localhost (96-89-128-221-static.hfc.comcastbusiness.net [96.89.128.221]) (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 291C414CEC643; Wed, 13 Feb 2019 16:34:27 -0800 (PST) Date: Wed, 13 Feb 2019 16:34:26 -0800 (PST) Message-Id: <20190213.163426.603453137542648612.davem@davemloft.net> To: lucien.xin@gmail.com Cc: linux-kernel@vger.kernel.org, netdev@vger.kernel.org, linux-sctp@vger.kernel.org, marcelo.leitner@gmail.com, nhorman@tuxdriver.com Subject: Re: [PATCH net] sctp: set stream ext to NULL after freeing it in sctp_stream_outq_migrate From: David Miller In-Reply-To: <0cb9e543c21495df48c3723044d6c9f64f238eca.1549968661.git.lucien.xin@gmail.com> References: <0cb9e543c21495df48c3723044d6c9f64f238eca.1549968661.git.lucien.xin@gmail.com> X-Mailer: Mew version 6.8 on Emacs 26.1 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]); Wed, 13 Feb 2019 16:34:27 -0800 (PST) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Xin Long Date: Tue, 12 Feb 2019 18:51:01 +0800 > In sctp_stream_init(), after sctp_stream_outq_migrate() freed the > surplus streams' ext, but sctp_stream_alloc_out() returns -ENOMEM, > stream->outcnt will not be set to 'outcnt'. > > With the bigger value on stream->outcnt, when closing the assoc and > freeing its streams, the ext of those surplus streams will be freed > again since those stream exts were not set to NULL after freeing in > sctp_stream_outq_migrate(). Then the invalid-free issue reported by > syzbot would be triggered. > > We fix it by simply setting them to NULL after freeing. > > Fixes: 5bbbbe32a431 ("sctp: introduce stream scheduler foundations") > Reported-by: syzbot+58e480e7b28f2d890bfd@syzkaller.appspotmail.com > Signed-off-by: Xin Long Also applied and queued up for -stable, thanks.