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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 44D87C43603 for ; Tue, 17 Dec 2019 11:54:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 19734207FF for ; Tue, 17 Dec 2019 11:54:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727328AbfLQLyM (ORCPT ); Tue, 17 Dec 2019 06:54:12 -0500 Received: from charlotte.tuxdriver.com ([70.61.120.58]:50113 "EHLO smtp.tuxdriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726141AbfLQLyL (ORCPT ); Tue, 17 Dec 2019 06:54:11 -0500 Received: from 2606-a000-111b-43ee-0000-0000-0000-115f.inf6.spectrum.com ([2606:a000:111b:43ee::115f] helo=localhost) by smtp.tuxdriver.com with esmtpsa (TLSv1:AES256-SHA:256) (Exim 4.63) (envelope-from ) id 1ihBQN-0008M7-17; Tue, 17 Dec 2019 06:54:05 -0500 Date: Tue, 17 Dec 2019 06:53:58 -0500 From: Neil Horman To: Marcelo Ricardo Leitner Cc: syzbot , davem@davemloft.net, linux-kernel@vger.kernel.org, linux-sctp@vger.kernel.org, netdev@vger.kernel.org, syzkaller-bugs@googlegroups.com, vyasevich@gmail.com Subject: Re: memory leak in sctp_stream_init Message-ID: <20191217115358.GA730@hmswarspite.think-freely.org> References: <000000000000f531080599c4073c@google.com> <20191216114828.GA20281@hmswarspite.think-freely.org> <20191216145638.GB5058@localhost.localdomain> <20191217003716.GC5058@localhost.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191217003716.GC5058@localhost.localdomain> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Dec 16, 2019 at 09:37:16PM -0300, Marcelo Ricardo Leitner wrote: > On Mon, Dec 16, 2019 at 11:56:38AM -0300, Marcelo Ricardo Leitner wrote: > ... > > Considering that genradix_prealloc() failure is not fatal, seems the > > fix here is to just ignore the failure in sctp_stream_alloc_out() and > > let genradix try again later on. > > Better yet, this fixes it here: > > ---8<--- > > diff --git a/net/sctp/stream.c b/net/sctp/stream.c > index df60b5ef24cb..e0b01bf912b3 100644 > --- a/net/sctp/stream.c > +++ b/net/sctp/stream.c > @@ -84,8 +84,10 @@ static int sctp_stream_alloc_out(struct sctp_stream *stream, __u16 outcnt, > return 0; > > ret = genradix_prealloc(&stream->out, outcnt, gfp); > - if (ret) > + if (ret) { > + genradix_free(&stream->out); > return ret; > + } > > stream->outcnt = outcnt; > return 0; > @@ -100,8 +102,10 @@ static int sctp_stream_alloc_in(struct sctp_stream *stream, __u16 incnt, > return 0; > > ret = genradix_prealloc(&stream->in, incnt, gfp); > - if (ret) > + if (ret) { > + genradix_free(&stream->in); > return ret; > + } > > stream->incnt = incnt; > return 0; > I get how that fixes this, but that doesn't really seem like the right fix in my mind. Shouldn't genradix_prealloc internally free any memory its allocated if it fails part way through its operation? Neil