From patchwork Wed Apr 1 16:17:32 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 228467 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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 00398C2D0F3 for ; Wed, 1 Apr 2020 16:31:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8D459212CC for ; Wed, 1 Apr 2020 16:31:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1585758660; bh=FOmBWtWn6+3QgLUu7/ZRMJz1EGVdTZYZfjvklXBdgdU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=k50Toj/YdvRMiSYhK2TcJeDaDhPyUgrl1Ua37xBxPOtRsCuPEOFcnc0L1wfM688ZS woajFuidtlg+4y5wwhw/0Ms8fhKBGxYJOiRMaGjknfKvknUqk4Srr0bdVrgSuU7LGD ZrCvLAAepB6PXkE3iKvhoX43/3v0N5EFGA8g3w2g= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387918AbgDAQa7 (ORCPT ); Wed, 1 Apr 2020 12:30:59 -0400 Received: from mail.kernel.org ([198.145.29.99]:56998 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387768AbgDAQa6 (ORCPT ); Wed, 1 Apr 2020 12:30:58 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 73A7D2137B; Wed, 1 Apr 2020 16:30:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1585758657; bh=FOmBWtWn6+3QgLUu7/ZRMJz1EGVdTZYZfjvklXBdgdU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=wlHMcy7jzqagMmZugur1G9yJ6oEH34QIm6AVLXgXRDcR4EbDA9afhl+RLEQKeiQPP iOwoECiBh8Dzt+mVb31anrE8QR3JJbipCQJF2j2Mt2FZyip7PsbVaavuW7h9ag9QTl rtlxUi9C7ZAKmLfwUAPFTz7NIZWGvPjaPnADf2lY= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jamal Hadi Salim , Jiri Pirko , John Fastabend , Cong Wang , "David S. Miller" , syzbot+f9b32aaacd60305d9687@syzkaller.appspotmail.com, syzbot+2f8c233f131943d6056d@syzkaller.appspotmail.com, syzbot+9c2df9fd5e9445b74e01@syzkaller.appspotmail.com Subject: [PATCH 4.4 36/91] net_sched: cls_route: remove the right filter from hashtable Date: Wed, 1 Apr 2020 18:17:32 +0200 Message-Id: <20200401161526.901169434@linuxfoundation.org> X-Mailer: git-send-email 2.26.0 In-Reply-To: <20200401161512.917494101@linuxfoundation.org> References: <20200401161512.917494101@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Cong Wang [ Upstream commit ef299cc3fa1a9e1288665a9fdc8bff55629fd359 ] route4_change() allocates a new filter and copies values from the old one. After the new filter is inserted into the hash table, the old filter should be removed and freed, as the final step of the update. However, the current code mistakenly removes the new one. This looks apparently wrong to me, and it causes double "free" and use-after-free too, as reported by syzbot. Reported-and-tested-by: syzbot+f9b32aaacd60305d9687@syzkaller.appspotmail.com Reported-and-tested-by: syzbot+2f8c233f131943d6056d@syzkaller.appspotmail.com Reported-and-tested-by: syzbot+9c2df9fd5e9445b74e01@syzkaller.appspotmail.com Fixes: 1109c00547fc ("net: sched: RCU cls_route") Cc: Jamal Hadi Salim Cc: Jiri Pirko Cc: John Fastabend Signed-off-by: Cong Wang Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/sched/cls_route.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/net/sched/cls_route.c +++ b/net/sched/cls_route.c @@ -540,8 +540,8 @@ static int route4_change(struct net *net fp = &b->ht[h]; for (pfp = rtnl_dereference(*fp); pfp; fp = &pfp->next, pfp = rtnl_dereference(*fp)) { - if (pfp == f) { - *fp = f->next; + if (pfp == fold) { + rcu_assign_pointer(*fp, fold->next); break; } }