Commit 89e23277 authored by Eric Dumazet's avatar Eric Dumazet Committed by Jakub Kicinski
Browse files

mptcp: mptcp_parse_option() fix for MPTCPOPT_MP_JOIN 



mptcp_parse_option() currently sets OPTIONS_MPTCP_MPJ, for the three
possible cases handled for MPTCPOPT_MP_JOIN option.

OPTIONS_MPTCP_MPJ is the combination of three flags:
- OPTION_MPTCP_MPJ_SYN
- OPTION_MPTCP_MPJ_SYNACK
- OPTION_MPTCP_MPJ_ACK

This is a problem, because backup, join_id, token, nonce and/or hmac fields
could be left uninitialized in some cases.

Distinguish the three cases, as following patches will need this step.

Fixes: f296234c ("mptcp: Add handling of incoming MP_JOIN requests")
Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Cc: Florian Westphal <fw@strlen.de>
Cc: Peter Krystad <peter.krystad@linux.intel.com>
Cc: Matthieu Baerts <matttbe@kernel.org>
Cc: Mat Martineau <martineau@kernel.org>
Cc: Geliang Tang <geliang.tang@linux.dev>
Reviewed-by: default avatarSimon Horman <horms@kernel.org>
Acked-by: default avatarPaolo Abeni <pabeni@redhat.com>
Reviewed-by: default avatarMat Martineau <martineau@kernel.org>
Link: https://lore.kernel.org/r/20240111194917.4044654-2-edumazet@google.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent cbdd50ec

net/mptcp/options.c

+3 −3
Original line number Diff line number Diff line
@@ -123,8 +123,8 @@ static void mptcp_parse_option(const struct sk_buff *skb, 
		break;



	case MPTCPOPT_MP_JOIN:

		mp_opt->suboptions |= OPTIONS_MPTCP_MPJ;

		if (opsize == TCPOLEN_MPTCP_MPJ_SYN) {

			mp_opt->suboptions |= OPTION_MPTCP_MPJ_SYN;

			mp_opt->backup = *ptr++ & MPTCPOPT_BACKUP;

			mp_opt->join_id = *ptr++;

			mp_opt->token = get_unaligned_be32(ptr);
@@ -135,6 +135,7 @@ static void mptcp_parse_option(const struct sk_buff *skb, 
				 mp_opt->backup, mp_opt->join_id,

				 mp_opt->token, mp_opt->nonce);

		} else if (opsize == TCPOLEN_MPTCP_MPJ_SYNACK) {

			mp_opt->suboptions |= OPTION_MPTCP_MPJ_SYNACK;

			mp_opt->backup = *ptr++ & MPTCPOPT_BACKUP;

			mp_opt->join_id = *ptr++;

			mp_opt->thmac = get_unaligned_be64(ptr);
@@ -145,11 +146,10 @@ static void mptcp_parse_option(const struct sk_buff *skb, 
				 mp_opt->backup, mp_opt->join_id,

				 mp_opt->thmac, mp_opt->nonce);

		} else if (opsize == TCPOLEN_MPTCP_MPJ_ACK) {

			mp_opt->suboptions |= OPTION_MPTCP_MPJ_ACK;

			ptr += 2;

			memcpy(mp_opt->hmac, ptr, MPTCPOPT_HMAC_LEN);

			pr_debug("MP_JOIN hmac");

		} else {

			mp_opt->suboptions &= ~OPTIONS_MPTCP_MPJ;

		}

		break;