After prior patches, inet6_csk_xmit() can reuse inet->cork.fl.u.ip6 if __sk_dst_check() returns a valid dst. Otherwise call inet6_csk_route_socket() to refresh inet->cork.fl.u.ip6 content and get a new dst. Signed-off-by: Eric Dumazet --- net/ipv6/inet6_connection_sock.c | 30 +++++++++++++++--------------- 1 file changed, 15 insertions(+), 15 deletions(-) diff --git a/net/ipv6/inet6_connection_sock.c b/net/ipv6/inet6_connection_sock.c index b6c4123aa0aeb803afdf807d8683156b710df2f6..11fc2f7de2fe981ddb48dc008bf7fd4ae1e4e2f6 100644 --- a/net/ipv6/inet6_connection_sock.c +++ b/net/ipv6/inet6_connection_sock.c @@ -81,13 +81,11 @@ static struct dst_entry *inet6_csk_route_socket(struct sock *sk, final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &np->final); rcu_read_unlock(); - dst = __sk_dst_check(sk, np->dst_cookie); - if (!dst) { - dst = ip6_dst_lookup_flow(sock_net(sk), sk, fl6, final_p); + dst = ip6_dst_lookup_flow(sock_net(sk), sk, fl6, final_p); + + if (!IS_ERR(dst)) + ip6_dst_store(sk, dst, false, false); - if (!IS_ERR(dst)) - ip6_dst_store(sk, dst, false, false); - } return dst; } @@ -98,20 +96,22 @@ int inet6_csk_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl_unused struct dst_entry *dst; int res; - dst = inet6_csk_route_socket(sk, fl6); - if (IS_ERR(dst)) { - WRITE_ONCE(sk->sk_err_soft, -PTR_ERR(dst)); - sk->sk_route_caps = 0; - kfree_skb(skb); - return PTR_ERR(dst); + dst = __sk_dst_check(sk, np->dst_cookie); + if (unlikely(!dst)) { + dst = inet6_csk_route_socket(sk, fl6); + if (IS_ERR(dst)) { + WRITE_ONCE(sk->sk_err_soft, -PTR_ERR(dst)); + sk->sk_route_caps = 0; + kfree_skb(skb); + return PTR_ERR(dst); + } + /* Restore final destination back after routing done */ + fl6->daddr = sk->sk_v6_daddr; } rcu_read_lock(); skb_dst_set_noref(skb, dst); - /* Restore final destination back after routing done */ - fl6->daddr = sk->sk_v6_daddr; - res = ip6_xmit(sk, skb, fl6, sk->sk_mark, rcu_dereference(np->opt), np->tclass, READ_ONCE(sk->sk_priority)); rcu_read_unlock(); -- 2.53.0.rc2.204.g2597b5adb4-goog