From patchwork Thu Jan 2 22:07:47 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: 234545 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,USER_AGENT_GIT autolearn=unavailable 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 D3B4FC3276C for ; Thu, 2 Jan 2020 22:52:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A68A720866 for ; Thu, 2 Jan 2020 22:52:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1578005575; bh=Wsgxuzfmf8MpLBh4cCjlsXtj18cok1RUznmA3pkYYJA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=ZFruz04Tlz3DLN80R3HRsCp4sxROxCv/Fi5d5p0hA83B04Ylx/IITarKh4d28u3Ls As34pbgt4OQzAADE56KsiSeRreJu3eN+h2K3YgP/JDriOc6PCxY0ZZlTy+0E5/Dsa7 EnadApQn2f3NEpSJ4HM8GbQD/xnAwknDFoDu7cew= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728791AbgABWW0 (ORCPT ); Thu, 2 Jan 2020 17:22:26 -0500 Received: from mail.kernel.org ([198.145.29.99]:42816 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727800AbgABWWW (ORCPT ); Thu, 2 Jan 2020 17:22:22 -0500 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 18B2520863; Thu, 2 Jan 2020 22:22:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1578003742; bh=Wsgxuzfmf8MpLBh4cCjlsXtj18cok1RUznmA3pkYYJA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=iVkg/xK3xfXrKH0P9f+IS0Frc9VqqmoKtYs3+4u9QsJBuJ3TJAzkcxGP/fEajwe0/ RA5FLTtLwJK796aCkPenUWwNXP7wr1FS4aMTlCu8cxyTiRaNIR88QXirgJfiehipbx 7JF9GS5JNaRuKD2QCYDj7l/ZbUC9HdmOB9tceBvo= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Antonio Messina , "David S. Miller" Subject: [PATCH 4.19 095/114] udp: fix integer overflow while computing available space in sk_rcvbuf Date: Thu, 2 Jan 2020 23:07:47 +0100 Message-Id: <20200102220038.721516462@linuxfoundation.org> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200102220029.183913184@linuxfoundation.org> References: <20200102220029.183913184@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: Antonio Messina [ Upstream commit feed8a4fc9d46c3126fb9fcae0e9248270c6321a ] 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 Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv4/udp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -1412,7 +1412,7 @@ int __udp_enqueue_schedule_skb(struct so * queue contains some other skb */ rmem = atomic_add_return(size, &sk->sk_rmem_alloc); - if (rmem > (size + sk->sk_rcvbuf)) + if (rmem > (size + (unsigned int)sk->sk_rcvbuf)) goto uncharge_drop; spin_lock(&list->lock);