3.5.7.9 -stable review patch. If anyone has any objections, please let me know.
------------------
From: Kees Cook <keescook@xxxxxxxxxxxx>
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 <keescook@xxxxxxxxxxxx>
Cc: Evgeniy Polyakov <zbr@xxxxxxxxxxx>
Cc: Matt Helsley <matthltc@xxxxxxxxxx>
Acked-by: Evgeniy Polyakov <zbr@xxxxxxxxxxx>
Acked-by: Matt Helsley <matthltc@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
[ luis: backported to 3.5 ]
Signed-off-by: Luis Henriques <luis.henriques@xxxxxxxxxxxxx>
---
drivers/connector/cn_proc.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/drivers/connector/cn_proc.c b/drivers/connector/cn_proc.c
index 77e1e6c..9d90e8c 100644
--- a/drivers/connector/cn_proc.c
+++ b/drivers/connector/cn_proc.c
@@ -303,7 +303,13 @@ static void cn_proc_mcast_ctl(struct cn_msg *msg,
if (msg->len != sizeof(*mc_op))
return;
- mc_op = (enum proc_cn_mcast_op*)msg->data;
+ /* 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:
atomic_inc(&proc_event_num_listeners);
@@ -315,6 +321,8 @@ static void cn_proc_mcast_ctl(struct cn_msg *msg,
err = EINVAL;
break;
}
+
+out:
cn_proc_ack(err, msg->seq, msg->ack);
}
--
1.8.1.2
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