Re: [PATCH net v2] l2tp: use sk_dst_check() to avoid race on sk->sk_dst_cache

From: Wei Wang Date: Fri, 10 Aug 2018 11:14:56 -0700 > From: Wei Wang > > In l2tp code, if it is a L2TP_UDP_ENCAP tunnel, tunnel->sk points to a > UDP socket. User could call sendmsg() on both this tunnel and the UDP > socket itself concurrently. As l2tp_xmit_skb() holds socket lock and call >

[PATCH net v2] l2tp: use sk_dst_check() to avoid race on sk->sk_dst_cache

From: Wei Wang In l2tp code, if it is a L2TP_UDP_ENCAP tunnel, tunnel->sk points to a UDP socket. User could call sendmsg() on both this tunnel and the UDP socket itself concurrently. As l2tp_xmit_skb() holds socket lock and call __sk_dst_check() to refresh sk->sk_dst_cache, while udpv6_sendmsg()