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authorKees Cook <keescook@chromium.org>2013-02-25 21:32:25 +0000
committerDavid S. Miller <davem@davemloft.net>2013-02-27 13:08:35 -0500
commite70ab977991964a5a7ad1182799451d067e62669 (patch)
tree1026f098ea84df13f0d94e5397d3a5ec6f913aeb
parent114a6f8b52163c0232fbcd7f3808ff04dc61a9b5 (diff)
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>
-rw-r--r--drivers/connector/cn_proc.c8
1 files changed, 8 insertions, 0 deletions
diff --git a/drivers/connector/cn_proc.c b/drivers/connector/cn_proc.c
index fce2000eec31..1110478dd0fd 100644
--- a/drivers/connector/cn_proc.c
+++ b/drivers/connector/cn_proc.c
@@ -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);
}