From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756634AbcBCWd5 (ORCPT ); Wed, 3 Feb 2016 17:33:57 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:46363 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752435AbcBCWdw (ORCPT ); Wed, 3 Feb 2016 17:33:52 -0500 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: "Eric W . Biederman" , Hannes Frederic Sowa , "David S . Miller" , Luis Henriques Subject: [PATCH 3.16.y-ckt 006/180] bridge: Only call /sbin/bridge-stp for the initial network namespace Date: Wed, 3 Feb 2016 22:30:12 +0000 Message-Id: <1454538786-12215-7-git-send-email-luis.henriques@canonical.com> In-Reply-To: <1454538786-12215-1-git-send-email-luis.henriques@canonical.com> References: <1454538786-12215-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.16 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.7-ckt24 -stable review patch. If anyone has any objections, please let me know. ---8<------------------------------------------------------------ From: Hannes Frederic Sowa commit ff62198553e43cdffa9d539f6165d3e83f8a42bc upstream. [I stole this patch from Eric Biederman. He wrote:] > There is no defined mechanism to pass network namespace information > into /sbin/bridge-stp therefore don't even try to invoke it except > for bridge devices in the initial network namespace. > > It is possible for unprivileged users to cause /sbin/bridge-stp to be > invoked for any network device name which if /sbin/bridge-stp does not > guard against unreasonable arguments or being invoked twice on the > same network device could cause problems. [Hannes: changed patch using netns_eq] Cc: Eric W. Biederman Signed-off-by: Eric W. Biederman Signed-off-by: Hannes Frederic Sowa Signed-off-by: David S. Miller Signed-off-by: Luis Henriques --- net/bridge/br_stp_if.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/net/bridge/br_stp_if.c b/net/bridge/br_stp_if.c index 9a0005aee9ad..15022fdfab70 100644 --- a/net/bridge/br_stp_if.c +++ b/net/bridge/br_stp_if.c @@ -128,7 +128,10 @@ static void br_stp_start(struct net_bridge *br) char *argv[] = { BR_STP_PROG, br->dev->name, "start", NULL }; char *envp[] = { NULL }; - r = call_usermodehelper(BR_STP_PROG, argv, envp, UMH_WAIT_PROC); + if (net_eq(dev_net(br->dev), &init_net)) + r = call_usermodehelper(BR_STP_PROG, argv, envp, UMH_WAIT_PROC); + else + r = -ENOENT; spin_lock_bh(&br->lock);