From: Antonio Quartulli <[email protected]>
Some subsystems, like BPF SOCKMAP, set sk_user_data without
actually setting the encap_type.
For this reason, we must make sure that the type is the
one ovpn expects before dereferencing sk_user_data.
Failing to do so may lead to out-of-bounds reads.
Fixes: f6226ae7a0cd ("ovpn: introduce the ovpn_socket object")
Signed-off-by: Antonio Quartulli <[email protected]>
---
drivers/net/ovpn/socket.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/drivers/net/ovpn/socket.c b/drivers/net/ovpn/socket.c
index 517caa64a4fe..6cbeb2caaeec 100644
--- a/drivers/net/ovpn/socket.c
+++ b/drivers/net/ovpn/socket.c
@@ -162,6 +162,15 @@ struct ovpn_socket *ovpn_socket_new(struct socket *sock,
struct ovpn_peer *peer)
rcu_read_lock();
ovpn_sock = rcu_dereference_sk_user_data(sk);
if (ovpn_sock) {
+ /* something else filled the sk_user_data without
+ * setting the encap_type. Reject the socket.
+ */
+ if (!type) {
+ ovpn_sock = ERR_PTR(-EBUSY);
+ rcu_read_unlock();
+ goto sock_release;
+ }
+
/* socket owned by another ovpn instance, we can't use
it */
if (ovpn_sock->ovpn != peer->ovpn) {
ovpn_sock = ERR_PTR(-EBUSY);
--
2.53.0
_______________________________________________
Openvpn-devel mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/openvpn-devel
