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!