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=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 3B19BC3276D for ; Thu, 2 Jan 2020 22:49:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F2F9120866 for ; Thu, 2 Jan 2020 22:49:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1578005393; bh=NUPF5Gpjm26pdH3c01yife+I/Qz3oOyID/puu7PriXo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=cTfpk47q2nt8VJRrB+pbo1gkjg1itHLU1ndRnkC19bcVlXoZZ87ATgxm/l+keeHbw m4x6eHMAo40xTIFIHxLm1W+CRdsKJZYNOLGPkYeS6KBnGeQn/+XqzDL0bVKLD59XV6 RyYkc4cv4XjtpWn0FwfqWPyvGH0TFaiWFSS4FJt0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731213AbgABWtw (ORCPT ); Thu, 2 Jan 2020 17:49:52 -0500 Received: from mail.kernel.org ([198.145.29.99]:53318 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729076AbgABW0Q (ORCPT ); Thu, 2 Jan 2020 17:26:16 -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 6590B21835; Thu, 2 Jan 2020 22:26:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1578003975; bh=NUPF5Gpjm26pdH3c01yife+I/Qz3oOyID/puu7PriXo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=CM9f43j6P4DlQbfnq/XgcOIy4X0qTl6b3CJbdctRQgfDC4lemiXOU5S2ePr31N5g/ GDFWbLRINEkv4IuR5oRRrsxT29uOAQLzYNQBVw+8FtHum+OwFpTIGAQ3PLtYemylbq Z2bxfu6epzHQ0pwZe2NBRevtsnwKu6h7h8Iby9ow= 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 4.14 77/91] udp: fix integer overflow while computing available space in sk_rcvbuf Date: Thu, 2 Jan 2020 23:07:59 +0100 Message-Id: <20200102220448.435931821@linuxfoundation.org> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200102220356.856162165@linuxfoundation.org> References: <20200102220356.856162165@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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 @@ -1338,7 +1338,7 @@ 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);