diff options
Diffstat (limited to 'net/ipv6/tcp_ipv6.c')
| -rw-r--r-- | net/ipv6/tcp_ipv6.c | 21 |
1 files changed, 18 insertions, 3 deletions
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index 578ab6305c3f..0ce52d46e4f8 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -348,11 +348,20 @@ failure: static void tcp_v6_mtu_reduced(struct sock *sk) { struct dst_entry *dst; + u32 mtu; if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE)) return; - dst = inet6_csk_update_pmtu(sk, tcp_sk(sk)->mtu_info); + mtu = READ_ONCE(tcp_sk(sk)->mtu_info); + + /* Drop requests trying to increase our current mss. + * Check done in __ip6_rt_update_pmtu() is too late. + */ + if (tcp_mtu_to_mss(sk, mtu) >= tcp_sk(sk)->mss_cache) + return; + + dst = inet6_csk_update_pmtu(sk, mtu); if (!dst) return; @@ -433,6 +442,8 @@ static int tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, } if (type == ICMPV6_PKT_TOOBIG) { + u32 mtu = ntohl(info); + /* We are not interested in TCP_LISTEN and open_requests * (SYN-ACKs send out by Linux are always <576bytes so * they should go through unfragmented). @@ -443,7 +454,11 @@ static int tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, if (!ip6_sk_accept_pmtu(sk)) goto out; - tp->mtu_info = ntohl(info); + if (mtu < IPV6_MIN_MTU) + goto out; + + WRITE_ONCE(tp->mtu_info, mtu); + if (!sock_owned_by_user(sk)) tcp_v6_mtu_reduced(sk); else if (!test_and_set_bit(TCP_MTU_REDUCED_DEFERRED, @@ -540,7 +555,7 @@ static int tcp_v6_send_synack(const struct sock *sk, struct dst_entry *dst, opt = ireq->ipv6_opt; if (!opt) opt = rcu_dereference(np->opt); - err = ip6_xmit(sk, skb, fl6, sk->sk_mark, opt, + err = ip6_xmit(sk, skb, fl6, skb->mark ? : sk->sk_mark, opt, tclass, sk->sk_priority); rcu_read_unlock(); err = net_xmit_eval(err); |