From: Paolo Abeni <pabeni@redhat.com>

commit 0c1f78a49af721490a5ad70b73e8b4d382465dae upstream.

The current accounting for MP_FAIL and FASTCLOSE is not very
accurate: both can be increased even when the related option is
not really sent. Move the accounting into the correct place.

Fixes: eb7f33654dc1 ("mptcp: add the mibs for MP_FAIL")
Fixes: 1e75629cb964 ("mptcp: add the mibs for MP_FASTCLOSE")
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>
[ Conflicts, because commit f284c0c77321 ("mptcp: implement fastclose
  xmit path") is not in this version. That's OK, the new helper added
  by this commit doesn't need to be modified. ]
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
---
 net/mptcp/options.c | 1 +
 net/mptcp/subflow.c | 4 +---
 2 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/net/mptcp/options.c b/net/mptcp/options.c
index d1443c5732c8..501c818bf7dc 100644
--- a/net/mptcp/options.c
+++ b/net/mptcp/options.c
@@ -793,6 +793,7 @@ static bool mptcp_established_options_mp_fail(struct sock *sk,
 	opts->fail_seq = subflow->map_seq;
 
 	pr_debug("MP_FAIL fail_seq=%llu\n", opts->fail_seq);
+	MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_MPFAILTX);
 
 	return true;
 }
diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c
index 2bf7f65b0afe..6a7c48397e3d 100644
--- a/net/mptcp/subflow.c
+++ b/net/mptcp/subflow.c
@@ -963,10 +963,8 @@ static enum mapping_status validate_data_csum(struct sock *ssk, struct sk_buff *
 				 subflow->map_data_csum);
 	if (unlikely(csum)) {
 		MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_DATACSUMERR);
-		if (subflow->mp_join || subflow->valid_csum_seen) {
+		if (subflow->mp_join || subflow->valid_csum_seen)
 			subflow->send_mp_fail = 1;
-			MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_MPFAILTX);
-		}
 		return subflow->mp_join ? MAPPING_INVALID : MAPPING_DUMMY;
 	}
 
-- 
2.50.0

This is a note to let you know that I've just added the patch titled

    mptcp: fix error mibs accounting

to the 5.15-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     mptcp-fix-error-mibs-accounting.patch
and it can be found in the queue-5.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


From stable+bounces-165647-greg=kroah.com@vger.kernel.org Thu Jul 31 13:24:24 2025
From: "Matthieu Baerts (NGI0)" <matttbe@kernel.org>
Date: Thu, 31 Jul 2025 13:23:56 +0200
Subject: mptcp: fix error mibs accounting
To: mptcp@lists.linux.dev, stable@vger.kernel.org, gregkh@linuxfoundation.org
Cc: Paolo Abeni <pabeni@redhat.com>, sashal@kernel.org, Mat Martineau <mathew.j.martineau@linux.intel.com>, Jakub Kicinski <kuba@kernel.org>, "Matthieu Baerts (NGI0)" <matttbe@kernel.org>
Message-ID: <20250731112353.2638719-10-matttbe@kernel.org>

From: Paolo Abeni <pabeni@redhat.com>

commit 0c1f78a49af721490a5ad70b73e8b4d382465dae upstream.

The current accounting for MP_FAIL and FASTCLOSE is not very
accurate: both can be increased even when the related option is
not really sent. Move the accounting into the correct place.

Fixes: eb7f33654dc1 ("mptcp: add the mibs for MP_FAIL")
Fixes: 1e75629cb964 ("mptcp: add the mibs for MP_FASTCLOSE")
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>
[ Conflicts, because commit f284c0c77321 ("mptcp: implement fastclose
  xmit path") is not in this version. That's OK, the new helper added
  by this commit doesn't need to be modified. ]
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 net/mptcp/options.c |    1 +
 net/mptcp/subflow.c |    4 +---
 2 files changed, 2 insertions(+), 3 deletions(-)

--- a/net/mptcp/options.c
+++ b/net/mptcp/options.c
@@ -793,6 +793,7 @@ static bool mptcp_established_options_mp
 	opts->fail_seq = subflow->map_seq;
 
 	pr_debug("MP_FAIL fail_seq=%llu\n", opts->fail_seq);
+	MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_MPFAILTX);
 
 	return true;
 }
--- a/net/mptcp/subflow.c
+++ b/net/mptcp/subflow.c
@@ -963,10 +963,8 @@ static enum mapping_status validate_data
 				 subflow->map_data_csum);
 	if (unlikely(csum)) {
 		MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_DATACSUMERR);
-		if (subflow->mp_join || subflow->valid_csum_seen) {
+		if (subflow->mp_join || subflow->valid_csum_seen)
 			subflow->send_mp_fail = 1;
-			MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_MPFAILTX);
-		}
 		return subflow->mp_join ? MAPPING_INVALID : MAPPING_DUMMY;
 	}
 


Patches currently in stable-queue which might be from matttbe@kernel.org are

queue-5.15/mptcp-drop-unused-sk-in-mptcp_push_release.patch
queue-5.15/selftests-mptcp-connect-also-cover-alt-modes.patch
queue-5.15/mptcp-drop-skb-if-mptcp-skb-extension-allocation-fails.patch
queue-5.15/selftests-mptcp-connect-also-cover-checksum.patch
queue-5.15/selftests-mptcp-make-sendfile-selftest-work.patch
queue-5.15/selftests-mptcp-initialize-variables-to-quiet-gcc-12-warnings.patch
queue-5.15/mptcp-pm-kernel-flush-do-not-reset-add_addr-limit.patch
queue-5.15/mptcp-do-not-queue-data-on-closed-subflows.patch
queue-5.15/selftests-mptcp-add-missing-join-check.patch
queue-5.15/mptcp-fix-error-mibs-accounting.patch
queue-5.15/mptcp-introduce-mapping_bad_csum.patch