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=-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=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 080AEC3276C for ; Thu, 2 Jan 2020 22:57:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CD40120866 for ; Thu, 2 Jan 2020 22:57:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1578005842; bh=231M9ZcOHkbunKVp1/YyJEDypQXx8MuXr0Vb+2TFM1k=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=p+V2mn34ENAUuKdp34I7LmdNi2C5YaHSzN6m+RyOZAFgNRXx9dc7nK48TbOlpGdam u71PFQ9w/1z4gPrj3P1NepwYwaplaxSahE/IWXVHfjHqG1DtHty8LAsOJ30e1cUxq0 6xYzTeXrWbkOvLjDPD1JvkDOVz7VQxbH+QpmdU78= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728335AbgABW5V (ORCPT ); Thu, 2 Jan 2020 17:57:21 -0500 Received: from mail.kernel.org ([198.145.29.99]:59448 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728091AbgABWRI (ORCPT ); Thu, 2 Jan 2020 17:17:08 -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 9FE27227BF; Thu, 2 Jan 2020 22:17:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1578003428; bh=231M9ZcOHkbunKVp1/YyJEDypQXx8MuXr0Vb+2TFM1k=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=e/okBfdPv0fRpo2xCJVLoJJuuvUgXuE9cWu9iJ2en6hRaaj1xKpOmafx1yvsvJhfL sPQcGQcSQLG15efmqs5/3GtzOoDhaNYbgz1sGl3X7UjndRBJAf6envLLHQD9zkAng0 E60LO4TBBx7Ul/b8al/KRVikNMhxJ75Nmp9d3i+4= 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 5.4 157/191] udp: fix integer overflow while computing available space in sk_rcvbuf Date: Thu, 2 Jan 2020 23:07:19 +0100 Message-Id: <20200102215846.228365652@linuxfoundation.org> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200102215829.911231638@linuxfoundation.org> References: <20200102215829.911231638@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 @@ -1475,7 +1475,7 @@ 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);