Commit e72e4032 authored by Paolo Abeni's avatar Paolo Abeni Committed by Jakub Kicinski
Browse files

mptcp: set msk local address earlier 

The mptcp_pm_nl_get_local_id() code assumes that the msk local address
is available at that point. For passive sockets, we initialize such
address at accept() time.

Depending on the running configuration and the user-space timing, a
passive MPJ subflow can join the msk socket before accept() completes.

In such case, the PM assigns a wrong local id to the MPJ subflow
and later PM netlink operations will end-up touching the wrong/unexpected
subflow.

All the above causes sporadic self-tests failures, especially when
the host is heavy loaded.

Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/308


Fixes: 01cacb00 ("mptcp: add netlink-based PM")
Fixes: d045b9eb ("mptcp: introduce implicit endpoints")
Reviewed-by: default avatarMat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
Signed-off-by: default avatarMat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 4a4b6848

net/mptcp/protocol.c

+1 −2
Original line number Diff line number Diff line
@@ -2952,7 +2952,7 @@ static void mptcp_close(struct sock *sk, long timeout) 
	sock_put(sk);

}



static void mptcp_copy_inaddrs(struct sock *msk, const struct sock *ssk)

void mptcp_copy_inaddrs(struct sock *msk, const struct sock *ssk)

{

#if IS_ENABLED(CONFIG_MPTCP_IPV6)

	const struct ipv6_pinfo *ssk6 = inet6_sk(ssk);
@@ -3699,7 +3699,6 @@ static int mptcp_stream_accept(struct socket *sock, struct socket *newsock, 
		if (mptcp_is_fully_established(newsk))

			mptcp_pm_fully_established(msk, msk->first, GFP_KERNEL);



		mptcp_copy_inaddrs(newsk, msk->first);

		mptcp_rcv_space_init(msk, msk->first);

		mptcp_propagate_sndbuf(newsk, msk->first);

net/mptcp/protocol.h

+1 −0
Original line number Diff line number Diff line
@@ -599,6 +599,7 @@ int mptcp_is_checksum_enabled(const struct net *net); 
int mptcp_allow_join_id0(const struct net *net);

unsigned int mptcp_stale_loss_cnt(const struct net *net);

int mptcp_get_pm_type(const struct net *net);

void mptcp_copy_inaddrs(struct sock *msk, const struct sock *ssk);

void mptcp_subflow_fully_established(struct mptcp_subflow_context *subflow,

				     struct mptcp_options_received *mp_opt);

bool __mptcp_retransmit_pending_data(struct sock *sk);

net/mptcp/subflow.c

+7 −0
Original line number Diff line number Diff line
@@ -723,6 +723,8 @@ static struct sock *subflow_syn_recv_sock(const struct sock *sk, 
				goto dispose_child;

			}



			if (new_msk)

				mptcp_copy_inaddrs(new_msk, child);

			subflow_drop_ctx(child);

			goto out;

		}
@@ -750,6 +752,11 @@ static struct sock *subflow_syn_recv_sock(const struct sock *sk, 
			ctx->conn = new_msk;

			new_msk = NULL;



			/* set msk addresses early to ensure mptcp_pm_get_local_id()

			 * uses the correct data

			 */

			mptcp_copy_inaddrs(ctx->conn, child);



			/* with OoO packets we can reach here without ingress

			 * mpc option

			 */