From e72e4032637f4646554794ac28a3abecc6c2416d Mon Sep 17 00:00:00 2001
From: Paolo Abeni <pabeni@redhat.com>
Date: Fri, 21 Oct 2022 15:58:54 -0700
Subject: [PATCH] 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: 01cacb00b35c ("mptcp: add netlink-based PM")
Fixes: d045b9eb95a9 ("mptcp: introduce implicit endpoints")
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
net/mptcp/protocol.c | 3 +--
net/mptcp/protocol.h | 1 +
net/mptcp/subflow.c | 7 +++++++
3 files changed, 9 insertions(+), 2 deletions(-)
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index f599ad44ed24c..e33f9caf409d6 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -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);
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index c0b5b4628f650..be19592441df9 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -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);
diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c
index 07dd23d0fe04a..02a54d59697b5 100644
--- a/net/mptcp/subflow.c
+++ b/net/mptcp/subflow.c
@@ -723,6 +723,8 @@ create_child:
goto dispose_child;
}
+ if (new_msk)
+ mptcp_copy_inaddrs(new_msk, child);
subflow_drop_ctx(child);
goto out;
}
@@ -750,6 +752,11 @@ create_child:
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
*/
--
2.30.2