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=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 DFDADC43219 for ; Thu, 2 May 2019 02:31:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B100E2085A for ; Thu, 2 May 2019 02:31:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726320AbfEBCbc (ORCPT ); Wed, 1 May 2019 22:31:32 -0400 Received: from shards.monkeyblade.net ([23.128.96.9]:44194 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726183AbfEBCbc (ORCPT ); Wed, 1 May 2019 22:31:32 -0400 Received: from localhost (adsl-173-228-226-134.prtc.net [173.228.226.134]) (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 1C0361433EB17; Wed, 1 May 2019 19:31:31 -0700 (PDT) Date: Wed, 01 May 2019 22:31:27 -0400 (EDT) Message-Id: <20190501.223127.269942837516364133.davem@davemloft.net> To: edumazet@google.com Cc: netdev@vger.kernel.org, eric.dumazet@gmail.com, pabeni@redhat.com, syzkaller@googlegroups.com Subject: Re: [PATCH net] udp: fix GRO packet of death From: David Miller In-Reply-To: <20190502015628.22215-1-edumazet@google.com> References: <20190502015628.22215-1-edumazet@google.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, 01 May 2019 19:31:31 -0700 (PDT) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Eric Dumazet Date: Wed, 1 May 2019 18:56:28 -0700 > syzbot was able to crash host by sending UDP packets with a 0 payload. > > TCP does not have this issue since we do not aggregate packets without > payload. > > Since dev_gro_receive() sets gso_size based on skb_gro_len(skb) > it seems not worth trying to cope with padded packets. ... > Fixes: e20cf8d3f1f7 ("udp: implement GRO for plain UDP sockets.") > Signed-off-by: Eric Dumazet > Cc: Paolo Abeni > Reported-by: syzbot Ugh :( Applied and queued up for -stable, thanks Eric.