From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <SRS0=+gZy=2O=vger.kernel.org=linux-kernel-owner@kernel.org>
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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,
	MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 ED796C2D0C3
	for <linux-kernel@archiver.kernel.org>; Tue, 24 Dec 2019 22:54:48 +0000 (UTC)
Received: from vger.kernel.org (vger.kernel.org [209.132.180.67])
	by mail.kernel.org (Postfix) with ESMTP id B142420663
	for <linux-kernel@archiver.kernel.org>; Tue, 24 Dec 2019 22:54:48 +0000 (UTC)
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
        id S1726283AbfLXWyr (ORCPT
        <rfc822;linux-kernel@archiver.kernel.org>);
        Tue, 24 Dec 2019 17:54:47 -0500
Received: from shards.monkeyblade.net ([23.128.96.9]:57250 "EHLO
        shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
        with ESMTP id S1726224AbfLXWyr (ORCPT
        <rfc822;linux-kernel@vger.kernel.org>);
        Tue, 24 Dec 2019 17:54:47 -0500
Received: from localhost (unknown [IPv6:2601:601:9f00:1c3::3d5])
        (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 6E0CB154C8767;
        Tue, 24 Dec 2019 14:54:46 -0800 (PST)
Date:   Tue, 24 Dec 2019 14:54:43 -0800 (PST)
Message-Id: <20191224.145443.2006645470880449664.davem@davemloft.net>
To:     amessina@google.com
Cc:     kuznet@ms2.inr.ac.ru, yoshfuji@linux-ipv6.org,
        netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] udp: fix integer overflow while computing available
 space in sk_rcvbuf
From:   David Miller <davem@davemloft.net>
In-Reply-To: <20191219140803.135164-1-amessina@google.com>
References: <20191219140803.135164-1-amessina@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]); Tue, 24 Dec 2019 14:54:46 -0800 (PST)
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

From: Antonio Messina <amessina@google.com>
Date: Thu, 19 Dec 2019 15:08:03 +0100

> When the size of the receive buffer for a socket is close to 2^31 when
> computing if we have enough space in the buffer to copy a packet from
> the queue to the buffer we might hit an integer overflow.
> 
> When an user set net.core.rmem_default to a value close to 2^31 UDP
> packets are dropped because of this overflow. This can be visible, for
> instance, with failure to resolve hostnames.
> 
> This can be fixed by casting sk_rcvbuf (which is an int) to unsigned
> int, similarly to how it is done in TCP.
> 
> Signed-off-by: Antonio Messina <amessina@google.com>

Applied and queued up for -stable, thanks.