From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Cyrus-Session-Id: sloti22d1t05-866468-1519070784-2-11265375577536171530 X-Sieve: CMU Sieve 3.0 X-Spam-known-sender: no X-Spam-score: 0.0 X-Spam-hits: BAYES_00 -1.9, HEADER_FROM_DIFFERENT_DOMAINS 0.001, RCVD_IN_DNSWL_HI -5, T_RP_MATCHES_RCVD -0.01, LANGUAGES en, BAYES_USED global, SA_VERSION 3.4.0 X-Spam-source: IP='209.132.180.67', Host='vger.kernel.org', Country='US', FromHeader='com', MailFrom='org' X-Spam-charsets: plain='UTF-8' X-Resolved-to: greg@kroah.com X-Delivered-to: greg@kroah.com X-Mail-from: stable-owner@vger.kernel.org ARC-Seal: i=1; a=rsa-sha256; cv=none; d=messagingengine.com; s=arctest; t=1519070784; b=hUbvK4olnfQs2+pVIB5frBBXmf1Kkfehl6oasGzXqU8rOIF xW2/hbHTnyiajg6gl766zOUUIvCfWzngCu3mu7rNA76GRtuhqFwdCkRjqAv+CuOc 9O5jTI7MUthB7PM0zGe4eIYVRNP0z78brpP7yG99Q8eFfgAPBv5q8bEEED/rXaT9 jO+MDXATkTCku9gCVVT44g4Tr0Nr7xdKvoqy3q3wNOmOFxdz5mrZ+kFjV4DGBSWT kvrE4N0Yqol1LR5ze7s55ahjatC7G1Lv1sVaFU0pPHrX1xrUQp9f3NLEJj84F3Bx dwbjad3429Q//5Ti0gS4Sa4yDSgd3USmLCl2RLA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=mime-version:in-reply-to:references:from :date:message-id:subject:to:cc:content-type:sender:list-id; s= arctest; t=1519070784; bh=AXiRN/ZojQ8ULmzhxuCartAuo0trE7Et/TgeSp QdHS0=; b=UcfO/jVAMNklFQXzFau0cqQfD2I1/EhSttMCRiPCg+/6KfCx5fG1GY JHiHCBVs54n8fMwOA79Nm9dbgiL/ZejlRd+fRWuCE3VkI8d24gWr4vFvBy43gcgy 0YzEhUu2WwZRd29dvAQsFE1nHcsNMKG9kOq9j/ggLuxbP4KQGcSzondkGLgfxYBf JKbY/2tPJFQPwWlm9KKa1GK8AI90Rx9PkvdzyoGlKere/vrR0Bg1MPchMJqpHJvm VuF4Tim7lTkS13J31xnGMLprbUR3blgnoyfaw+WtnPiKxIK4rk3UT1NcZbw9+mfY UB+S3iAWjHEBib2rImUjOql0x2NL/Qkw== ARC-Authentication-Results: i=1; mx3.messagingengine.com; arc=none (no signatures found); dkim=pass (2048-bit rsa key sha256) header.d=google.com header.i=@google.com header.b=j8x04ENk x-bits=2048 x-keytype=rsa x-algorithm=sha256 x-selector=20161025; dmarc=pass (p=reject,has-list-id=yes,d=none) header.from=google.com; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-google-dkim=pass (2048-bit rsa key) header.d=1e100.net header.i=@1e100.net header.b=Rk0xVyWF; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=google.com header.result=pass header_is_org_domain=yes Authentication-Results: mx3.messagingengine.com; arc=none (no signatures found); dkim=pass (2048-bit rsa key sha256) header.d=google.com header.i=@google.com header.b=j8x04ENk x-bits=2048 x-keytype=rsa x-algorithm=sha256 x-selector=20161025; dmarc=pass (p=reject,has-list-id=yes,d=none) header.from=google.com; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-google-dkim=pass (2048-bit rsa key) header.d=1e100.net header.i=@1e100.net header.b=Rk0xVyWF; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=google.com header.result=pass header_is_org_domain=yes Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753727AbeBSUGX (ORCPT ); Mon, 19 Feb 2018 15:06:23 -0500 Received: from mail-wm0-f68.google.com ([74.125.82.68]:38042 "EHLO mail-wm0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753611AbeBSUGW (ORCPT ); Mon, 19 Feb 2018 15:06:22 -0500 X-Google-Smtp-Source: AH8x224Dz9QP6E9WfOmXIYQHGAQOFmSnmN20mRjq5OZ43c8hkB+z7FtwBS/t6ZpoMHRnWw1+GwKSZJzmdcAbm53/8sc= MIME-Version: 1.0 In-Reply-To: <1519069941.3422.65.camel@codethink.co.uk> References: <20180129123847.507563674@linuxfoundation.org> <20180129123850.261403857@linuxfoundation.org> <1519069573.3422.63.camel@codethink.co.uk> <1519069941.3422.65.camel@codethink.co.uk> From: Eric Dumazet Date: Mon, 19 Feb 2018 12:06:19 -0800 Message-ID: Subject: Re: [PATCH 4.4 60/74] ipv6: fix udpv6 sendmsg crash caused by too small MTU To: Ben Hutchings Cc: Mike Maloney , stable@vger.kernel.org, syzbot , "David S. Miller" , Greg Kroah-Hartman , LKML Content-Type: text/plain; charset="UTF-8" Sender: stable-owner@vger.kernel.org X-Mailing-List: stable@vger.kernel.org X-getmail-retrieved-from-mailbox: INBOX X-Mailing-List: linux-kernel@vger.kernel.org List-ID: On Mon, Feb 19, 2018 at 11:52 AM, Ben Hutchings wrote: > On Mon, 2018-02-19 at 20:46 +0100, Ben Hutchings wrote: >> On Mon, 2018-01-29 at 13:57 +0100, Greg Kroah-Hartman wrote: >> > 4.4-stable review patch. If anyone has any objections, please let me know. >> > >> > ------------------ >> > >> > From: Mike Maloney >> > >> > >> > [ Upstream commit 749439bfac6e1a2932c582e2699f91d329658196 ] >> >> [...] >> > --- a/net/ipv6/ip6_output.c >> > +++ b/net/ipv6/ip6_output.c >> > @@ -1246,14 +1246,16 @@ static int ip6_setup_cork(struct sock *s >> > v6_cork->tclass = tclass; >> > if (rt->dst.flags & DST_XFRM_TUNNEL) >> > mtu = np->pmtudisc >= IPV6_PMTUDISC_PROBE ? >> > - rt->dst.dev->mtu : dst_mtu(&rt->dst); >> > + READ_ONCE(rt->dst.dev->mtu) : dst_mtu(&rt->dst); >> > else >> > mtu = np->pmtudisc >= IPV6_PMTUDISC_PROBE ? >> > - rt->dst.dev->mtu : dst_mtu(rt->dst.path); >> > + READ_ONCE(rt->dst.dev->mtu) : dst_mtu(rt->dst.path); >> > if (np->frag_size < mtu) { >> > if (np->frag_size) >> > mtu = np->frag_size; >> > } >> > + if (mtu < IPV6_MIN_MTU) >> > + return -EINVAL; >> >> This error path appears to leak a reference to rt->dst. > > Never mind, I see that the callers release it. Yes, I agree this is quite confusing :/