A UDP socket may retain a detachable tunnel GRO callback while it remains visible to userspace. If userspace subsequently changes UDP_ENCAP, replacing the encapsulation callbacks without first retiring GRO leaves the old callback lifetime and frag-list acceptance state active.
Validate the requested encapsulation type, then detach such a GRO callback before installing the new encapsulation implementation. Existing sockets are unaffected because no current user enables detachable GRO callbacks. UDP_ENCAP already permits userspace to change the encapsulation type of a live socket even when driver state remains attached to it. Resolving that pre-existing ownership issue is outside the scope of this change. This only keeps detachable GRO state and callback lifetimes consistent when the existing transition occurs; it does not make cross-encapsulator ownership handoff supported. Signed-off-by: Ralf Lici <[email protected]> --- No changes since v1 https://lore.kernel.org/openvpn-devel/99b9cccf9845899bc36e92165d9443499fe8a284.1794314969.git.r...@mandelbit.com/ net/ipv4/udp.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index d62452c0f663..2d16a220c42d 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -3019,6 +3019,9 @@ int udp_lib_setsockopt(struct sock *sk, int level, int optname, case 0: #ifdef CONFIG_XFRM case UDP_ENCAP_ESPINUDP: + if (udp_test_bit(GRO_RCV_DETACHABLE, sk)) + udp_tunnel_detach_gro(sk); + set_xfrm_gro_udp_encap_rcv(val, sk->sk_family, sk); #if IS_ENABLED(CONFIG_IPV6) if (sk->sk_family == AF_INET6) @@ -3031,6 +3034,9 @@ int udp_lib_setsockopt(struct sock *sk, int level, int optname, #endif fallthrough; case UDP_ENCAP_L2TPINUDP: + if (udp_test_bit(GRO_RCV_DETACHABLE, sk)) + udp_tunnel_detach_gro(sk); + WRITE_ONCE(up->encap_type, val); udp_tunnel_encap_enable(sk); break; -- 2.56.0 _______________________________________________ Openvpn-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/openvpn-devel
