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 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 92FBCC4360F for ; Thu, 28 Mar 2019 04:59:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6B1722075E for ; Thu, 28 Mar 2019 04:59:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725916AbfC1E7z (ORCPT ); Thu, 28 Mar 2019 00:59:55 -0400 Received: from shards.monkeyblade.net ([23.128.96.9]:33974 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725777AbfC1E7z (ORCPT ); Thu, 28 Mar 2019 00:59:55 -0400 Received: from localhost (unknown [IPv6:2601:601:9f80:35cd::d71]) (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 94C4C108CA829; Wed, 27 Mar 2019 21:59:54 -0700 (PDT) Date: Wed, 27 Mar 2019 21:59:53 -0700 (PDT) Message-Id: <20190327.215953.1992775219057881382.davem@davemloft.net> To: pabeni@redhat.com Cc: netdev@vger.kernel.org, alexander.duyck@gmail.com, christoph.paasch@gmail.com Subject: Re: [PATCH net] net: datagram: fix unbounded loop in __skb_try_recv_datagram() From: David Miller In-Reply-To: References: 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, 27 Mar 2019 21:59:54 -0700 (PDT) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Paolo Abeni Date: Mon, 25 Mar 2019 14:18:06 +0100 > Christoph reported a stall while peeking datagram with an offset when > busy polling is enabled. __skb_try_recv_datagram() uses as the loop > termination condition 'queue empty'. When peeking, the socket > queue can be not empty, even when no additional packets are received. > > Address the issue explicitly checking for receive queue changes, > as currently done by __skb_wait_for_more_packets(). > > Fixes: 2b5cd0dfa384 ("net: Change return type of sk_busy_loop from bool to void") > Reported-and-tested-by: Christoph Paasch > Signed-off-by: Paolo Abeni Applied and queued up for -stable, thanks Paolo.