Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932727AbdLVIzX (ORCPT ); Fri, 22 Dec 2017 03:55:23 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:35266 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932685AbdLVIzI (ORCPT ); Fri, 22 Dec 2017 03:55:08 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Alexander Duyck , Eric Dumazet , "David S. Miller" , Sasha Levin Subject: [PATCH 4.9 048/104] net: Do not allow negative values for busy_read and busy_poll sysctl interfaces Date: Fri, 22 Dec 2017 09:46:14 +0100 Message-Id: <20171222084613.324492070@linuxfoundation.org> X-Mailer: git-send-email 2.15.1 In-Reply-To: <20171222084609.262099650@linuxfoundation.org> References: <20171222084609.262099650@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1802 Lines: 51 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Alexander Duyck [ Upstream commit 95f255211396958c718aef8c45e3923b5211ea7b ] This change basically codifies what I think was already the limitations on the busy_poll and busy_read sysctl interfaces. We weren't checking the lower bounds and as such could input negative values. The behavior when that was used was dependent on the architecture. In order to prevent any issues with that I am just disabling support for values less than 0 since this way we don't have to worry about any odd behaviors. By limiting the sysctl values this way it also makes it consistent with how we handle the SO_BUSY_POLL socket option since the value appears to be reported as a signed integer value and negative values are rejected. Signed-off-by: Alexander Duyck Acked-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- net/core/sysctl_net_core.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) --- a/net/core/sysctl_net_core.c +++ b/net/core/sysctl_net_core.c @@ -369,14 +369,16 @@ static struct ctl_table net_core_table[] .data = &sysctl_net_busy_poll, .maxlen = sizeof(unsigned int), .mode = 0644, - .proc_handler = proc_dointvec + .proc_handler = proc_dointvec_minmax, + .extra1 = &zero, }, { .procname = "busy_read", .data = &sysctl_net_busy_read, .maxlen = sizeof(unsigned int), .mode = 0644, - .proc_handler = proc_dointvec + .proc_handler = proc_dointvec_minmax, + .extra1 = &zero, }, #endif #ifdef CONFIG_NET_SCHED