From d216a50eb96cec065ae6b538b15999d4819967da Mon Sep 17 00:00:00 2001 From: Davide Caratti Date: Mon, 15 Mar 2021 11:41:16 +0100 Subject: [PATCH] mptcp: fix ADD_ADDR HMAC in case port is specified MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Currently, Linux computes the HMAC contained in ADD_ADDR sub-option using the Address Id and the IP Address, and hardcodes a destination port equal to zero. This is not ok for ADD_ADDR with port: ensure to account for the endpoint port when computing the HMAC, in compliance with RFC8684 §3.4.1. Fixes: 1d0d3d44ede7 ("mptcp: add port support for ADD_ADDR suboption writing") Reviewed-by: Mat Martineau Acked-by: Geliang Tang Signed-off-by: Davide Caratti Signed-off-by: David S. Miller --- net/mptcp/options.c | 24 ++++++++++++++---------- 1 file changed, 14 insertions(+), 10 deletions(-) diff --git a/net/mptcp/options.c b/net/mptcp/options.c index 444a38681e93e..89a4225ed3211 100644 --- a/net/mptcp/options.c +++ b/net/mptcp/options.c @@ -567,15 +567,15 @@ static bool mptcp_established_options_dss(struct sock *sk, struct sk_buff *skb, } static u64 add_addr_generate_hmac(u64 key1, u64 key2, u8 addr_id, - struct in_addr *addr) + struct in_addr *addr, u16 port) { u8 hmac[SHA256_DIGEST_SIZE]; u8 msg[7]; msg[0] = addr_id; memcpy(&msg[1], &addr->s_addr, 4); - msg[5] = 0; - msg[6] = 0; + msg[5] = port >> 8; + msg[6] = port & 0xFF; mptcp_crypto_hmac_sha(key1, key2, msg, 7, hmac); @@ -584,15 +584,15 @@ static u64 add_addr_generate_hmac(u64 key1, u64 key2, u8 addr_id, #if IS_ENABLED(CONFIG_MPTCP_IPV6) static u64 add_addr6_generate_hmac(u64 key1, u64 key2, u8 addr_id, - struct in6_addr *addr) + struct in6_addr *addr, u16 port) { u8 hmac[SHA256_DIGEST_SIZE]; u8 msg[19]; msg[0] = addr_id; memcpy(&msg[1], &addr->s6_addr, 16); - msg[17] = 0; - msg[18] = 0; + msg[17] = port >> 8; + msg[18] = port & 0xFF; mptcp_crypto_hmac_sha(key1, key2, msg, 19, hmac); @@ -646,7 +646,8 @@ static bool mptcp_established_options_add_addr(struct sock *sk, struct sk_buff * opts->ahmac = add_addr_generate_hmac(msk->local_key, msk->remote_key, opts->addr_id, - &opts->addr); + &opts->addr, + opts->port); } } #if IS_ENABLED(CONFIG_MPTCP_IPV6) @@ -657,7 +658,8 @@ static bool mptcp_established_options_add_addr(struct sock *sk, struct sk_buff * opts->ahmac = add_addr6_generate_hmac(msk->local_key, msk->remote_key, opts->addr_id, - &opts->addr6); + &opts->addr6, + opts->port); } } #endif @@ -962,12 +964,14 @@ static bool add_addr_hmac_valid(struct mptcp_sock *msk, if (mp_opt->family == MPTCP_ADDR_IPVERSION_4) hmac = add_addr_generate_hmac(msk->remote_key, msk->local_key, - mp_opt->addr_id, &mp_opt->addr); + mp_opt->addr_id, &mp_opt->addr, + mp_opt->port); #if IS_ENABLED(CONFIG_MPTCP_IPV6) else hmac = add_addr6_generate_hmac(msk->remote_key, msk->local_key, - mp_opt->addr_id, &mp_opt->addr6); + mp_opt->addr_id, &mp_opt->addr6, + mp_opt->port); #endif pr_debug("msk=%p, ahmac=%llu, mp_opt->ahmac=%llu\n", -- 2.39.5