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=-3.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 7F5D2C432C1 for ; Tue, 24 Sep 2019 12:53:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5412F207FD for ; Tue, 24 Sep 2019 12:53:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2440991AbfIXMxC (ORCPT ); Tue, 24 Sep 2019 08:53:02 -0400 Received: from shards.monkeyblade.net ([23.128.96.9]:51158 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728379AbfIXMxC (ORCPT ); Tue, 24 Sep 2019 08:53:02 -0400 Received: from localhost (231-157-167-83.reverse.alphalink.fr [83.167.157.231]) (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 ADA9315163DFE; Tue, 24 Sep 2019 05:53:00 -0700 (PDT) Date: Tue, 24 Sep 2019 14:52:57 +0200 (CEST) Message-Id: <20190924.145257.2013712373872209531.davem@davemloft.net> To: Jason@zx2c4.com Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: Re: [PATCH] ipv6: do not free rt if FIB_LOOKUP_NOREF is set on suppress rule From: David Miller In-Reply-To: <20190924073615.31704-1-Jason@zx2c4.com> References: <20190924073615.31704-1-Jason@zx2c4.com> X-Mailer: Mew version 6.8 on Emacs 26.2 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]); Tue, 24 Sep 2019 05:53:01 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "Jason A. Donenfeld" Date: Tue, 24 Sep 2019 09:36:15 +0200 > Commit 7d9e5f422150 removed references from certain dsts, but accounting > for this never translated down into the fib6 suppression code. This bug > was triggered by WireGuard users who use wg-quick(8), which uses the > "suppress-prefix" directive to ip-rule(8) for routing all of their > internet traffic without routing loops. The test case in the link of > this commit reliably triggers various crashes due to the use-after-free > caused by the reference underflow. > > Cc: stable@vger.kernel.org > Fixes: 7d9e5f422150 ("ipv6: convert major tx path to use RT6_LOOKUP_F_DST_NOREF") > Test-case: https://git.zx2c4.com/WireGuard/commit/?id=ad66532000f7a20b149e47c5eb3a957362c8e161 > Signed-off-by: Jason A. Donenfeld Please make such test cases integratabe into the selftests area for networking and submit it along with this fix. Otherwise this code will regress. Thank you.