From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Kees Cook , Evgeniy Polyakov , Matt Helsley , "David S. Miller" , Ben Hutchings , Qiang Huang Subject: [PATCH 3.4 49/99] proc connector: reject unprivileged listener bumps Date: Fri, 7 Mar 2014 17:07:45 -0800 Message-Id: <20140308010613.180842254@linuxfoundation.org> In-Reply-To: <20140308010611.468206150@linuxfoundation.org> References: <20140308010611.468206150@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Kees Cook commit e70ab977991964a5a7ad1182799451d067e62669 upstream. While PROC_CN_MCAST_LISTEN/IGNORE is entirely advisory, it was possible for an unprivileged user to turn off notifications for all listeners by sending PROC_CN_MCAST_IGNORE. Instead, require the same privileges as required for a multicast bind. Signed-off-by: Kees Cook Cc: Evgeniy Polyakov Cc: Matt Helsley Acked-by: Evgeniy Polyakov Acked-by: Matt Helsley Signed-off-by: David S. Miller [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings Cc: Qiang Huang Signed-off-by: Greg Kroah-Hartman --- drivers/connector/cn_proc.c | 8 ++++++++ 1 file changed, 8 insertions(+) --- a/drivers/connector/cn_proc.c +++ b/drivers/connector/cn_proc.c @@ -331,6 +331,12 @@ static void cn_proc_mcast_ctl(struct cn_ if (msg->len != sizeof(*mc_op)) return; + /* Can only change if privileged. */ + if (!capable(CAP_NET_ADMIN)) { + err = EPERM; + goto out; + } + mc_op = (enum proc_cn_mcast_op*)msg->data; switch (*mc_op) { case PROC_CN_MCAST_LISTEN: @@ -343,6 +349,8 @@ static void cn_proc_mcast_ctl(struct cn_ err = EINVAL; break; } + +out: cn_proc_ack(err, msg->seq, msg->ack); }