6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet <edumazet@xxxxxxxxxx> [ Upstream commit 6d5a12eb91224d707f8691dccb40a5719fe5466d ] 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@xxxxxxxxxx> Reviewed-by: Willem de Bruijn <willemb@xxxxxxxxxx> Signed-off-by: Paolo Abeni <pabeni@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- net/ipv4/udp.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index b2aa7777521f6..65abc92a81bd0 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -2714,10 +2714,12 @@ 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: -- 2.42.0