From: Davide Caratti dcaratti@redhat.com
[ Upstream commit 13832ae2755395b2585500c85b64f5109a44227e ]
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 ยง3.4.1.
Fixes: 22fb85ffaefb ("mptcp: add port support for ADD_ADDR suboption writing") Reviewed-by: Mat Martineau mathew.j.martineau@linux.intel.com Acked-by: Geliang Tang geliangtang@gmail.com Signed-off-by: Davide Caratti dcaratti@redhat.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- 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 2e26e39169b8..37ef0bf098f6 100644 --- a/net/mptcp/options.c +++ b/net/mptcp/options.c @@ -555,15 +555,15 @@ 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);
@@ -572,15 +572,15 @@ 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);
@@ -634,7 +634,8 @@ 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) @@ -645,7 +646,8 @@ 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 @@ -922,12 +924,14 @@ 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",