diff mbox series

[net,1/3] mptcp: set msk local address earlier

Message ID 20221021225856.88119-2-mathew.j.martineau@linux.intel.com (mailing list archive)
State Accepted
Commit e72e4032637f4646554794ac28a3abecc6c2416d
Delegated to: Netdev Maintainers
Headers show
Series mptcp: Fixes for 6.1 | expand

Checks

Context Check Description
netdev/tree_selection success Clearly marked for net
netdev/fixes_present success Fixes tag present in non-next series
netdev/subject_prefix success Link
netdev/cover_letter success Series has a cover letter
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 5 this patch: 5
netdev/cc_maintainers success CCed 8 of 8 maintainers
netdev/build_clang success Errors and warnings before: 7 this patch: 7
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success Fixes tag looks correct
netdev/build_allmodconfig_warn success Errors and warnings before: 5 this patch: 5
netdev/checkpatch warning WARNING: line length of 84 exceeds 80 columns
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Mat Martineau Oct. 21, 2022, 10:58 p.m. UTC 
From: Paolo Abeni <pabeni@redhat.com>

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>
---
 net/mptcp/protocol.c | 3 +--
 net/mptcp/protocol.h | 1 +
 net/mptcp/subflow.c  | 7 +++++++
 3 files changed, 9 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index f599ad44ed24..e33f9caf409d 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 c0b5b4628f65..be19592441df 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 07dd23d0fe04..02a54d59697b 100644
--- a/net/mptcp/subflow.c
+++ b/net/mptcp/subflow.c
@@ -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
 			 */