udp: add missing WRITE_ONCE() around up->encap_rcv

UDP_ENCAP_ESPINUDP_NON_IKE setsockopt() writes over up->encap_rcv
while other cpus read it.

Fixes: 067b207b281d ("[UDP]: Cleanup UDP encapsulation code")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 1debc10a0f029e47ffe90aaff60727b6bb7309cc..db43907b9a3e8d8f05c98e6a873415e6731261f4 100644 (file)
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -2675,10 +2675,12 @@ int udp_lib_setsockopt(struct sock *sk, int level, int optname,
                case UDP_ENCAP_ESPINUDP_NON_IKE:
 #if IS_ENABLED(CONFIG_IPV6)
                        if (sk->sk_family == AF_INET6)
-                               up->encap_rcv = ipv6_stub->xfrm6_udp_encap_rcv;
+                               WRITE_ONCE(up->encap_rcv,
+                                          ipv6_stub->xfrm6_udp_encap_rcv);
                        else
 #endif
-                               up->encap_rcv = xfrm4_udp_encap_rcv;
+                               WRITE_ONCE(up->encap_rcv,
+                                          xfrm4_udp_encap_rcv);
 #endif
                        fallthrough;
                case UDP_ENCAP_L2TPINUDP: