lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Message-ID: <20231004223629.166300-12-dima@arista.com> Date: Wed, 4 Oct 2023 23:36:15 +0100 From: Dmitry Safonov <dima@...sta.com> To: David Ahern <dsahern@...nel.org>, Eric Dumazet <edumazet@...gle.com>, Paolo Abeni <pabeni@...hat.com>, Jakub Kicinski <kuba@...nel.org>, "David S. Miller" <davem@...emloft.net> Cc: linux-kernel@...r.kernel.org, Dmitry Safonov <dima@...sta.com>, Andy Lutomirski <luto@...capital.net>, Ard Biesheuvel <ardb@...nel.org>, Bob Gilligan <gilligan@...sta.com>, Dan Carpenter <error27@...il.com>, David Laight <David.Laight@...lab.com>, Dmitry Safonov <0x7f454c46@...il.com>, Donald Cassidy <dcassidy@...hat.com>, Eric Biggers <ebiggers@...nel.org>, "Eric W. Biederman" <ebiederm@...ssion.com>, Francesco Ruggeri <fruggeri05@...il.com>, "Gaillardetz, Dominik" <dgaillar@...na.com>, Herbert Xu <herbert@...dor.apana.org.au>, Hideaki YOSHIFUJI <yoshfuji@...ux-ipv6.org>, Ivan Delalande <colona@...sta.com>, Leonard Crestez <cdleonard@...il.com>, "Nassiri, Mohammad" <mnassiri@...na.com>, Salam Noureddine <noureddine@...sta.com>, Simon Horman <simon.horman@...igine.com>, "Tetreault, Francois" <ftetreau@...na.com>, netdev@...r.kernel.org Subject: [PATCH v13 net-next 11/23] net/tcp: Sign SYN-ACK segments with TCP-AO Similarly to RST segments, wire SYN-ACKs to TCP-AO. tcp_rsk_used_ao() is handy here to check if the request socket used AO and needs a signature on the outgoing segments. Co-developed-by: Francesco Ruggeri <fruggeri@...sta.com> Signed-off-by: Francesco Ruggeri <fruggeri@...sta.com> Co-developed-by: Salam Noureddine <noureddine@...sta.com> Signed-off-by: Salam Noureddine <noureddine@...sta.com> Signed-off-by: Dmitry Safonov <dima@...sta.com> Acked-by: David Ahern <dsahern@...nel.org> --- include/net/tcp.h | 3 ++ include/net/tcp_ao.h | 6 ++++ net/ipv4/tcp_ao.c | 22 +++++++++++++ net/ipv4/tcp_ipv4.c | 1 + net/ipv4/tcp_output.c | 72 +++++++++++++++++++++++++++++++++---------- net/ipv6/tcp_ao.c | 22 +++++++++++++ net/ipv6/tcp_ipv6.c | 1 + 7 files changed, 111 insertions(+), 16 deletions(-) diff --git a/include/net/tcp.h b/include/net/tcp.h index 7cb8c75cb98b..e2e4e09fb608 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -2181,6 +2181,9 @@ struct tcp_request_sock_ops { struct request_sock *req, int sndid, int rcvid); int (*ao_calc_key)(struct tcp_ao_key *mkt, u8 *key, struct request_sock *sk); + int (*ao_synack_hash)(char *ao_hash, struct tcp_ao_key *mkt, + struct request_sock *req, const struct sk_buff *skb, + int hash_offset, u32 sne); #endif #ifdef CONFIG_SYN_COOKIES __u32 (*cookie_init_seq)(const struct sk_buff *skb, diff --git a/include/net/tcp_ao.h b/include/net/tcp_ao.h index d04b17971c3c..56c2e34ad7d2 100644 --- a/include/net/tcp_ao.h +++ b/include/net/tcp_ao.h @@ -147,6 +147,9 @@ int tcp_ao_prepare_reset(const struct sock *sk, struct sk_buff *skb, int tcp_v4_parse_ao(struct sock *sk, int cmd, sockptr_t optval, int optlen); struct tcp_ao_key *tcp_v4_ao_lookup(const struct sock *sk, struct sock *addr_sk, int sndid, int rcvid); +int tcp_v4_ao_synack_hash(char *ao_hash, struct tcp_ao_key *mkt, + struct request_sock *req, const struct sk_buff *skb, + int hash_offset, u32 sne); int tcp_v4_ao_calc_key_sk(struct tcp_ao_key *mkt, u8 *key, const struct sock *sk, __be32 sisn, __be32 disn, bool send); @@ -181,6 +184,9 @@ int tcp_v6_ao_hash_skb(char *ao_hash, struct tcp_ao_key *key, const struct sock *sk, const struct sk_buff *skb, const u8 *tkey, int hash_offset, u32 sne); int tcp_v6_parse_ao(struct sock *sk, int cmd, sockptr_t optval, int optlen); +int tcp_v6_ao_synack_hash(char *ao_hash, struct tcp_ao_key *ao_key, + struct request_sock *req, const struct sk_buff *skb, + int hash_offset, u32 sne); void tcp_ao_established(struct sock *sk); void tcp_ao_finish_connect(struct sock *sk, struct sk_buff *skb); void tcp_ao_connect_init(struct sock *sk); diff --git a/net/ipv4/tcp_ao.c b/net/ipv4/tcp_ao.c index c8006b0cbb8a..0102d0662fca 100644 --- a/net/ipv4/tcp_ao.c +++ b/net/ipv4/tcp_ao.c @@ -568,6 +568,28 @@ int tcp_v4_ao_hash_skb(char *ao_hash, struct tcp_ao_key *key, tkey, hash_offset, sne); } +int tcp_v4_ao_synack_hash(char *ao_hash, struct tcp_ao_key *ao_key, + struct request_sock *req, const struct sk_buff *skb, + int hash_offset, u32 sne) +{ + void *hash_buf = NULL; + int err; + + hash_buf = kmalloc(tcp_ao_digest_size(ao_key), GFP_ATOMIC); + if (!hash_buf) + return -ENOMEM; + + err = tcp_v4_ao_calc_key_rsk(ao_key, hash_buf, req); + if (err) + goto out; + + err = tcp_ao_hash_skb(AF_INET, ao_hash, ao_key, req_to_sk(req), skb, + hash_buf, hash_offset, sne); +out: + kfree(hash_buf); + return err; +} + struct tcp_ao_key *tcp_v4_ao_lookup_rsk(const struct sock *sk, struct request_sock *req, int sndid, int rcvid) diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index c332a86c22c5..b4d26d893f9d 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -1680,6 +1680,7 @@ const struct tcp_request_sock_ops tcp_request_sock_ipv4_ops = { #ifdef CONFIG_TCP_AO .ao_lookup = tcp_v4_ao_lookup_rsk, .ao_calc_key = tcp_v4_ao_calc_key_rsk, + .ao_synack_hash = tcp_v4_ao_synack_hash, #endif #ifdef CONFIG_SYN_COOKIES .cookie_init_seq = cookie_v4_init_sequence, diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 5d2937a3e0d8..eb0db93291c1 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -887,7 +887,7 @@ static unsigned int tcp_synack_options(const struct sock *sk, struct request_sock *req, unsigned int mss, struct sk_buff *skb, struct tcp_out_options *opts, - const struct tcp_md5sig_key *md5, + const struct tcp_key *key, struct tcp_fastopen_cookie *foc, enum tcp_synack_type synack_type, struct sk_buff *syn_skb) @@ -895,8 +895,7 @@ static unsigned int tcp_synack_options(const struct sock *sk, struct inet_request_sock *ireq = inet_rsk(req); unsigned int remaining = MAX_TCP_OPTION_SPACE; -#ifdef CONFIG_TCP_MD5SIG - if (md5) { + if (tcp_key_is_md5(key)) { opts->options |= OPTION_MD5; remaining -= TCPOLEN_MD5SIG_ALIGNED; @@ -907,8 +906,11 @@ static unsigned int tcp_synack_options(const struct sock *sk, */ if (synack_type != TCP_SYNACK_COOKIE) ireq->tstamp_ok &= !ireq->sack_ok; + } else if (tcp_key_is_ao(key)) { + opts->options |= OPTION_AO; + remaining -= tcp_ao_len(key->ao_key); + ireq->tstamp_ok &= !ireq->sack_ok; } -#endif /* We always send an MSS option. */ opts->mss = mss; @@ -3656,7 +3658,6 @@ struct sk_buff *tcp_make_synack(const struct sock *sk, struct dst_entry *dst, { struct inet_request_sock *ireq = inet_rsk(req); const struct tcp_sock *tp = tcp_sk(sk); - struct tcp_md5sig_key *md5 = NULL; struct tcp_out_options opts; struct tcp_key key = {}; struct sk_buff *skb; @@ -3708,18 +3709,48 @@ struct sk_buff *tcp_make_synack(const struct sock *sk, struct dst_entry *dst, tcp_rsk(req)->snt_synack = tcp_skb_timestamp_us(skb); } -#ifdef CONFIG_TCP_MD5SIG +#if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO) rcu_read_lock(); - md5 = tcp_rsk(req)->af_specific->req_md5_lookup(sk, req_to_sk(req)); - if (md5) - key.type = TCP_KEY_MD5; #endif + if (tcp_rsk_used_ao(req)) { +#ifdef CONFIG_TCP_AO + struct tcp_ao_key *ao_key = NULL; + u8 maclen = tcp_rsk(req)->maclen; + u8 keyid = tcp_rsk(req)->ao_keyid; + + ao_key = tcp_sk(sk)->af_specific->ao_lookup(sk, req_to_sk(req), + keyid, -1); + /* If there is no matching key - avoid sending anything, + * especially usigned segments. It could try harder and lookup + * for another peer-matching key, but the peer has requested + * ao_keyid (RFC5925 RNextKeyID), so let's keep it simple here. + */ + if (unlikely(!ao_key || tcp_ao_maclen(ao_key) != maclen)) { + u8 key_maclen = ao_key ? tcp_ao_maclen(ao_key) : 0; + + rcu_read_unlock(); + kfree_skb(skb); + net_warn_ratelimited("TCP-AO: the keyid %u with maclen %u|%u from SYN packet is not present - not sending SYNACK\n", + keyid, maclen, key_maclen); + return NULL; + } + key.ao_key = ao_key; + key.type = TCP_KEY_AO; +#endif + } else { +#ifdef CONFIG_TCP_MD5SIG + key.md5_key = tcp_rsk(req)->af_specific->req_md5_lookup(sk, + req_to_sk(req)); + if (key.md5_key) + key.type = TCP_KEY_MD5; +#endif + } skb_set_hash(skb, READ_ONCE(tcp_rsk(req)->txhash), PKT_HASH_TYPE_L4); /* bpf program will be interested in the tcp_flags */ TCP_SKB_CB(skb)->tcp_flags = TCPHDR_SYN | TCPHDR_ACK; - tcp_header_size = tcp_synack_options(sk, req, mss, skb, &opts, md5, - foc, synack_type, - syn_skb) + sizeof(*th); + tcp_header_size = tcp_synack_options(sk, req, mss, skb, &opts, + &key, foc, synack_type, syn_skb) + + sizeof(*th); skb_push(skb, tcp_header_size); skb_reset_transport_header(skb); @@ -3739,15 +3770,24 @@ struct sk_buff *tcp_make_synack(const struct sock *sk, struct dst_entry *dst, /* RFC1323: The window in SYN & SYN/ACK segments is never scaled. */ th->window = htons(min(req->rsk_rcv_wnd, 65535U)); - tcp_options_write(th, NULL, NULL, &opts, &key); + tcp_options_write(th, NULL, tcp_rsk(req), &opts, &key); th->doff = (tcp_header_size >> 2); TCP_INC_STATS(sock_net(sk), TCP_MIB_OUTSEGS); -#ifdef CONFIG_TCP_MD5SIG /* Okay, we have all we need - do the md5 hash if needed */ - if (md5) + if (tcp_key_is_md5(&key)) { +#ifdef CONFIG_TCP_MD5SIG tcp_rsk(req)->af_specific->calc_md5_hash(opts.hash_location, - md5, req_to_sk(req), skb); + key.md5_key, req_to_sk(req), skb); +#endif + } else if (tcp_key_is_ao(&key)) { +#ifdef CONFIG_TCP_AO + tcp_rsk(req)->af_specific->ao_synack_hash(opts.hash_location, + key.ao_key, req, skb, + opts.hash_location - (u8 *)th, 0); +#endif + } +#if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO) rcu_read_unlock(); #endif diff --git a/net/ipv6/tcp_ao.c b/net/ipv6/tcp_ao.c index c9a6fa84f6ce..99753e12c08c 100644 --- a/net/ipv6/tcp_ao.c +++ b/net/ipv6/tcp_ao.c @@ -144,3 +144,25 @@ int tcp_v6_parse_ao(struct sock *sk, int cmd, { return tcp_parse_ao(sk, cmd, AF_INET6, optval, optlen); } + +int tcp_v6_ao_synack_hash(char *ao_hash, struct tcp_ao_key *ao_key, + struct request_sock *req, const struct sk_buff *skb, + int hash_offset, u32 sne) +{ + void *hash_buf = NULL; + int err; + + hash_buf = kmalloc(tcp_ao_digest_size(ao_key), GFP_ATOMIC); + if (!hash_buf) + return -ENOMEM; + + err = tcp_v6_ao_calc_key_rsk(ao_key, hash_buf, req); + if (err) + goto out; + + err = tcp_ao_hash_skb(AF_INET6, ao_hash, ao_key, req_to_sk(req), skb, + hash_buf, hash_offset, sne); +out: + kfree(hash_buf); + return err; +} diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index b5396e379c35..38d784236168 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -838,6 +838,7 @@ const struct tcp_request_sock_ops tcp_request_sock_ipv6_ops = { #ifdef CONFIG_TCP_AO .ao_lookup = tcp_v6_ao_lookup_rsk, .ao_calc_key = tcp_v6_ao_calc_key_rsk, + .ao_synack_hash = tcp_v6_ao_synack_hash, #endif #ifdef CONFIG_SYN_COOKIES .cookie_init_seq = cookie_v6_init_sequence, -- 2.42.0
Powered by blists - more mailing lists