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| author | Dmitry Safonov <dima@arista.com> | 2023-10-23 22:22:08 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2023-10-27 12:35:45 +0300 |
| commit | 953af8e3acb68d2db11937cec3bc5da31de5c12e (patch) | |
| tree | 2c56c02d543050285dd073b65827682066114e26 /net/ipv6/tcp_ipv6.c | |
| parent | 2717b5adea9e2558798c30eb0e93c01722edbb0a (diff) | |
| download | linux-953af8e3acb68d2db11937cec3bc5da31de5c12e.tar.xz | |
net/tcp: Ignore specific ICMPs for TCP-AO connections
Similarly to IPsec, RFC5925 prescribes:
">> A TCP-AO implementation MUST default to ignore incoming ICMPv4
messages of Type 3 (destination unreachable), Codes 2-4 (protocol
unreachable, port unreachable, and fragmentation needed -- ’hard
errors’), and ICMPv6 Type 1 (destination unreachable), Code 1
(administratively prohibited) and Code 4 (port unreachable) intended
for connections in synchronized states (ESTABLISHED, FIN-WAIT-1, FIN-
WAIT-2, CLOSE-WAIT, CLOSING, LAST-ACK, TIME-WAIT) that match MKTs."
A selftest (later in patch series) verifies that this attack is not
possible in this TCP-AO implementation.
Co-developed-by: Francesco Ruggeri <fruggeri@arista.com>
Signed-off-by: Francesco Ruggeri <fruggeri@arista.com>
Co-developed-by: Salam Noureddine <noureddine@arista.com>
Signed-off-by: Salam Noureddine <noureddine@arista.com>
Signed-off-by: Dmitry Safonov <dima@arista.com>
Acked-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv6/tcp_ipv6.c')
| -rw-r--r-- | net/ipv6/tcp_ipv6.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index 4dcbc13e9ec8..fa7050579e9a 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -396,6 +396,8 @@ static int tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, } if (sk->sk_state == TCP_TIME_WAIT) { + /* To increase the counter of ignored icmps for TCP-AO */ + tcp_ao_ignore_icmp(sk, AF_INET6, type, code); inet_twsk_put(inet_twsk(sk)); return 0; } @@ -406,6 +408,11 @@ static int tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, return 0; } + if (tcp_ao_ignore_icmp(sk, AF_INET6, type, code)) { + sock_put(sk); + return 0; + } + bh_lock_sock(sk); if (sock_owned_by_user(sk) && type != ICMPV6_PKT_TOOBIG) __NET_INC_STATS(net, LINUX_MIB_LOCKDROPPEDICMPS); |