Commit e70ab977 authored Feb 25, 2013 by Kees Cook Committed by David S. Miller Feb 27, 2013

proc connector: reject unprivileged listener bumps

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 <keescook@chromium.org>
Cc: Evgeniy Polyakov <zbr@ioremap.net>
Cc: Matt Helsley <matthltc@us.ibm.com>
Cc: stable@vger.kernel.org
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Acked-by: Matt Helsley <matthltc@us.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 114a6f8b

drivers/connector/cn_proc.c

+8 −0

Original line number	Diff line number	Diff line
		@@ -313,6 +313,12 @@ static void cn_proc_mcast_ctl(struct cn_msg *msg,
		(task_active_pid_ns(current) != &init_pid_ns))
		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:
		@@ -325,6 +331,8 @@ static void cn_proc_mcast_ctl(struct cn_msg *msg,
		err = EINVAL;
		break;
		}

		out:
		cn_proc_ack(err, msg->seq, msg->ack);
		}