Commit 9634cb35 authored by Matthieu Baerts (NGI0)'s avatar Matthieu Baerts (NGI0) Committed by Jakub Kicinski
Browse files

mptcp: pm: ADD_ADDR rtx: always decrease sk refcount 



When an ADD_ADDR is retransmitted, the sk is held in sk_reset_timer().
It should then be released in all cases at the end.

Some (unlikely) checks were returning directly instead of calling
sock_put() to decrease the refcount. Jump to a new 'exit' label to call
__sock_put() (which will become sock_put() in the next commit) to fix
this potential leak.

While at it, drop the '!msk' check which cannot happen because it is
never reset, and explicitly mark the remaining one as "unlikely".

Fixes: 00cfd77b ("mptcp: retransmit ADD_ADDR when timeout")
Cc: stable@vger.kernel.org
Reviewed-by: default avatarMat Martineau <martineau@kernel.org>
Signed-off-by: default avatarMatthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260505-net-mptcp-pm-fixes-7-1-rc3-v1-4-fca8091060a4@kernel.org


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 5cd6e0ad

net/mptcp/pm.c

+3 −5
Original line number Diff line number Diff line
@@ -331,11 +331,8 @@ static void mptcp_pm_add_timer(struct timer_list *timer) 


	pr_debug("msk=%p\n", msk);



	if (!msk)

		return;



	if (inet_sk_state_load(sk) == TCP_CLOSE)

		return;

	if (unlikely(inet_sk_state_load(sk) == TCP_CLOSE))

		goto exit;



	bh_lock_sock(sk);

	if (sock_owned_by_user(sk)) {
@@ -373,6 +370,7 @@ static void mptcp_pm_add_timer(struct timer_list *timer) 


out:

	bh_unlock_sock(sk);

exit:

	__sock_put(sk);

}