diff options
| author | Max Krummenacher <max.krummenacher@toradex.com> | 2021-10-16 13:04:24 +0200 |
|---|---|---|
| committer | Max Krummenacher <max.krummenacher@toradex.com> | 2021-10-16 13:04:24 +0200 |
| commit | f8e718054f4421d11638e370b933ccc6c77466ed (patch) | |
| tree | 973ff8cb8aed7d8e4da6a194456ddc01c206b7de /net/ipv6/tcp_ipv6.c | |
| parent | d900385139e5aa8d584dee92c87bb85d0226253e (diff) | |
| parent | 1392fe82d7fba00ba4a8e01968935f2b2085d5a4 (diff) | |
Merge tag 'v4.4.288' into toradex_vf_4.4
This is the 4.4.288 stable release
Signed-off-by: Max Krummenacher <max.krummenacher@toradex.com>
Diffstat (limited to 'net/ipv6/tcp_ipv6.c')
| -rw-r--r-- | net/ipv6/tcp_ipv6.c | 19 |
1 files changed, 17 insertions, 2 deletions
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index 53e15514d90d..68c9d033c718 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -308,11 +308,20 @@ 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; @@ -391,6 +400,8 @@ static void 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). @@ -401,7 +412,11 @@ static void 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, |