net/mptcp/ctrl.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
When a first MPTCP connection gets successfully established after a
blackhole period, 'active_disable_times' was supposed to be reset when
this connection was done via any non-loopback interfaces.
Unfortunately, the opposite condition was checked: only reset when the
connection was established via a loopback interface. Fixing this by
simply looking at the opposite.
This is similar to what is done with TCP FastOpen, see
tcp_fastopen_active_disable_ofo_check().
This patch is a follow-up of a previous discussion linked to commit
893c49a78d9f ("mptcp: Use __sk_dst_get() and dst_dev_rcu() in
mptcp_active_enable()."), see [1].
Fixes: 27069e7cb3d1 ("mptcp: disable active MPTCP in case of blackhole")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/4209a283-8822-47bd-95b7-87e96d9b7ea3@kernel.org [1]
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
---
Cc: Kuniyuki Iwashima <kuniyu@google.com>
Note: sending this fix to net-next, similar to commits 108a86c71c93
("mptcp: Call dst_release() in mptcp_active_enable().") and 893c49a78d9f
("mptcp: Use __sk_dst_get() and dst_dev_rcu() in mptcp_active_enable().").
Also to avoid conflicts, and because we are close to the merge windows.
---
net/mptcp/ctrl.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/mptcp/ctrl.c b/net/mptcp/ctrl.c
index e8ffa62ec183f3cd8156e3969ac4a7d0213a990b..d96130e49942e2fb878cd1897ad43c1d420fb233 100644
--- a/net/mptcp/ctrl.c
+++ b/net/mptcp/ctrl.c
@@ -507,7 +507,7 @@ void mptcp_active_enable(struct sock *sk)
rcu_read_lock();
dst = __sk_dst_get(sk);
dev = dst ? dst_dev_rcu(dst) : NULL;
- if (dev && (dev->flags & IFF_LOOPBACK))
+ if (!(dev && (dev->flags & IFF_LOOPBACK)))
atomic_set(&pernet->active_disable_times, 0);
rcu_read_unlock();
}
---
base-commit: b127e355f1af1e4a635ed8f78cb0d11c916613cf
change-id: 20250918-net-next-mptcp-blackhole-reset-loopback-d82c518e409f
Best regards,
--
Matthieu Baerts (NGI0) <matttbe@kernel.org>
Hello: This patch was applied to netdev/net-next.git (main) by Jakub Kicinski <kuba@kernel.org>: On Thu, 18 Sep 2025 10:50:18 +0200 you wrote: > When a first MPTCP connection gets successfully established after a > blackhole period, 'active_disable_times' was supposed to be reset when > this connection was done via any non-loopback interfaces. > > Unfortunately, the opposite condition was checked: only reset when the > connection was established via a loopback interface. Fixing this by > simply looking at the opposite. > > [...] Here is the summary with links: - [net-next] mptcp: reset blackhole on success with non-loopback ifaces https://git.kernel.org/netdev/net-next/c/833d4313bc1e You are awesome, thank you! -- Deet-doot-dot, I am a bot. https://korg.docs.kernel.org/patchwork/pwbot.html
On Thu, Sep 18, 2025 at 1:51 AM Matthieu Baerts (NGI0) <matttbe@kernel.org> wrote: > > When a first MPTCP connection gets successfully established after a > blackhole period, 'active_disable_times' was supposed to be reset when > this connection was done via any non-loopback interfaces. > > Unfortunately, the opposite condition was checked: only reset when the > connection was established via a loopback interface. Fixing this by > simply looking at the opposite. > > This is similar to what is done with TCP FastOpen, see > tcp_fastopen_active_disable_ofo_check(). > > This patch is a follow-up of a previous discussion linked to commit > 893c49a78d9f ("mptcp: Use __sk_dst_get() and dst_dev_rcu() in > mptcp_active_enable()."), see [1]. > > Fixes: 27069e7cb3d1 ("mptcp: disable active MPTCP in case of blackhole") > Cc: stable@vger.kernel.org > Link: https://lore.kernel.org/4209a283-8822-47bd-95b7-87e96d9b7ea3@kernel.org [1] > Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> > --- > Cc: Kuniyuki Iwashima <kuniyu@google.com> > Note: sending this fix to net-next, similar to commits 108a86c71c93 > ("mptcp: Call dst_release() in mptcp_active_enable().") and 893c49a78d9f > ("mptcp: Use __sk_dst_get() and dst_dev_rcu() in mptcp_active_enable()."). > Also to avoid conflicts, and because we are close to the merge windows. Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Thanks for the followup!
On Thu, Sep 18, 2025 at 10:50:18AM +0200, Matthieu Baerts (NGI0) wrote: > When a first MPTCP connection gets successfully established after a > blackhole period, 'active_disable_times' was supposed to be reset when > this connection was done via any non-loopback interfaces. > > Unfortunately, the opposite condition was checked: only reset when the > connection was established via a loopback interface. Fixing this by > simply looking at the opposite. > > This is similar to what is done with TCP FastOpen, see > tcp_fastopen_active_disable_ofo_check(). > > This patch is a follow-up of a previous discussion linked to commit > 893c49a78d9f ("mptcp: Use __sk_dst_get() and dst_dev_rcu() in > mptcp_active_enable()."), see [1]. > > Fixes: 27069e7cb3d1 ("mptcp: disable active MPTCP in case of blackhole") > Cc: stable@vger.kernel.org > Link: https://lore.kernel.org/4209a283-8822-47bd-95b7-87e96d9b7ea3@kernel.org [1] > Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> > --- > Cc: Kuniyuki Iwashima <kuniyu@google.com> > Note: sending this fix to net-next, similar to commits 108a86c71c93 > ("mptcp: Call dst_release() in mptcp_active_enable().") and 893c49a78d9f > ("mptcp: Use __sk_dst_get() and dst_dev_rcu() in mptcp_active_enable()."). > Also to avoid conflicts, and because we are close to the merge windows. Reviewed-by: Simon Horman <horms@kernel.org>
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