Patch "mptcp: fix bad RCVPRUNED mib accounting" has been added to the 5.15-stable tree

[<gregkh@linuxfoundation.org>]

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

    mptcp: fix bad RCVPRUNED mib 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-bad-rcvpruned-mib-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-66131-greg=kroah.com@vger.kernel.org Fri Aug  9 11:08:26 2024
From: "Matthieu Baerts (NGI0)" <matttbe@kernel.org>
Date: Fri,  9 Aug 2024 11:08:14 +0200
Subject: mptcp: fix bad RCVPRUNED mib accounting
To: stable@vger.kernel.org, gregkh@linuxfoundation.org
Cc: MPTCP Upstream <mptcp@lists.linux.dev>, Paolo Abeni <pabeni@redhat.com>, Mat Martineau <martineau@kernel.org>, Matthieu Baerts <matttbe@kernel.org>
Message-ID: <20240809090813.2700287-2-matttbe@kernel.org>

From: Paolo Abeni <pabeni@redhat.com>

commit 0a567c2a10033bf04ed618368d179bce6977984b upstream.

Since its introduction, the mentioned MIB accounted for the wrong
event: wake-up being skipped as not-needed on some edge condition
instead of incoming skb being dropped after landing in the (subflow)
receive queue.

Move the increment in the correct location.

Fixes: ce599c516386 ("mptcp: properly account bulk freed memory")
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
[ Conflicts in protocol.c, because the commit 6511882cdd82 ("mptcp:
  allocate fwd memory separately on the rx and tx path") is not in this
  version. The fix can still be applied before the 'goto drop'. ]
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 net/mptcp/protocol.c |    8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -288,8 +288,10 @@ static bool __mptcp_move_skb(struct mptc
 	if (!sk_rmem_schedule(sk, skb, skb->truesize)) {
 		int amount = sk_mem_pages(skb->truesize) << SK_MEM_QUANTUM_SHIFT;
 
-		if (ssk->sk_forward_alloc < amount)
+		if (ssk->sk_forward_alloc < amount) {
+			MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_RCVPRUNED);
 			goto drop;
+		}
 
 		ssk->sk_forward_alloc -= amount;
 		sk->sk_forward_alloc += amount;
@@ -774,10 +776,8 @@ void mptcp_data_ready(struct sock *sk, s
 		sk_rbuf = ssk_rbuf;
 
 	/* over limit? can't append more skbs to msk, Also, no need to wake-up*/
-	if (__mptcp_rmem(sk) > sk_rbuf) {
-		MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_RCVPRUNED);
+	if (__mptcp_rmem(sk) > sk_rbuf)
 		return;
-	}
 
 	/* Wake-up the reader only for in-sequence data */
 	mptcp_data_lock(sk);


Patches currently in stable-queue which might be from kroah.com@vger.kernel.org are

queue-5.15/mptcp-fix-nl-pm-announced-address-accounting.patch
queue-5.15/mptcp-distinguish-rcv-vs-sent-backup-flag-in-requests.patch
queue-5.15/mptcp-pm-fix-backup-support-in-signal-endpoints.patch
queue-5.15/mptcp-mib-count-mpj-with-backup-flag.patch
queue-5.15/selftests-mptcp-join-validate-backup-in-mpj.patch
queue-5.15/mptcp-export-local_address.patch
queue-5.15/mptcp-pm-only-set-request_bkup-flag-when-sending-mp_prio.patch
queue-5.15/mptcp-fix-bad-rcvpruned-mib-accounting.patch