From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A8C003CCFD2 for ; Mon, 18 May 2026 14:40:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779115245; cv=none; b=gRBjcbLEebnte/Z4tLtCuyaImthNuq80rjrtaqN/2pwcwM8V6kjd3QyiHJj/9bjU38PuhTFgWVs4OP7+3aIPqwoQsjLJjsEGetDFHD8PYLkYHAWB7uKU6EBYgWXdH80prWggipwKS3jjag2b07Hc8vJV+PEf0LanXczOyJz0oZo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779115245; c=relaxed/simple; bh=Z/ttCIPDWChr6uj09OT2vqed5zlrSKD5vgP5YAqbLZA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=W/PZrHuzeEGEzev+8ZkKaU/8lPIvJg4gqOAwfkcy6kbfpYhFGB3Zy+WFdRLjqI3Y6kwo3texYptwjFzPGkQF9sJyJB887HxC1KLaFYMCVcaopttnBnPip6CRXaNRkaQS0pFPUell0OvbyZwgdN2htBwnAF++tF6GOF7PAw8zNAo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=O99mOYnI; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="O99mOYnI" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 990FAC2BCB7; Mon, 18 May 2026 14:40:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1779115245; bh=Z/ttCIPDWChr6uj09OT2vqed5zlrSKD5vgP5YAqbLZA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=O99mOYnI5bBmvGXY18ojsCR6wcIrLDfTPzCSxT8pfVKAyShYRmvTjYUd62sdm5ExX 9zAjACd0Ms8mY6wm9PwXst/XIZh109AlPijitFVGHu76GghjfjuxeuzL9ue0nErLTL 0an6JJTcLOp1DArzkYomf0itiydtmmZXZz4FtOdSaL3tfKnovxkXBSU+nuD9ExrSMs Kqpj09A9Z72N84AmqIxxRhefi1Rw8F7ppvLzLN340HN12lZWHJi7cfZK+M94uZKzEE xXn5XDvsBD1Nqg8FXuXNmMAhSbRg5VdYpefLj9KymOMkdaVCcSkG81AWr85Mtfyt1y pTCqsgQfNGdQg== From: Sasha Levin To: stable@vger.kernel.org Cc: "Matthieu Baerts (NGI0)" , Mat Martineau , Jakub Kicinski , Sasha Levin Subject: [PATCH 5.15.y] mptcp: pm: ADD_ADDR rtx: fix potential data-race Date: Mon, 18 May 2026 10:40:42 -0400 Message-ID: <20260518144042.1361354-1-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <2026051216-stock-unloved-37a8@gregkh> References: <2026051216-stock-unloved-37a8@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: "Matthieu Baerts (NGI0)" [ Upstream commit 5cd6e0ad79d2615264f63929f8b457ad97ae550d ] This mptcp_pm_add_timer() helper is executed as a timer callback in softirq context. To avoid any data races, the socket lock needs to be held with bh_lock_sock(). If the socket is in use, retry again soon after, similar to what is done with the keepalive timer. Fixes: 00cfd77b9063 ("mptcp: retransmit ADD_ADDR when timeout") Cc: stable@vger.kernel.org Reviewed-by: Mat Martineau Signed-off-by: Matthieu Baerts (NGI0) Link: https://patch.msgid.link/20260505-net-mptcp-pm-fixes-7-1-rc3-v1-3-fca8091060a4@kernel.org Signed-off-by: Jakub Kicinski [ applied hunk to `net/mptcp/pm_netlink.c` instead of `net/mptcp/pm.c` ] Signed-off-by: Sasha Levin --- net/mptcp/pm_netlink.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c index 6fb14148a96e0..bdfeba7dd9f24 100644 --- a/net/mptcp/pm_netlink.c +++ b/net/mptcp/pm_netlink.c @@ -330,6 +330,13 @@ static void mptcp_pm_add_timer(struct timer_list *timer) if (!entry->addr.id) return; + bh_lock_sock(sk); + if (sock_owned_by_user(sk)) { + /* Try again later. */ + sk_reset_timer(sk, timer, jiffies + HZ / 20); + goto out; + } + if (mptcp_pm_should_add_signal_addr(msk)) { sk_reset_timer(sk, timer, jiffies + TCP_RTO_MAX / 8); goto out; @@ -358,6 +365,7 @@ static void mptcp_pm_add_timer(struct timer_list *timer) mptcp_pm_subflow_established(msk); out: + bh_unlock_sock(sk); __sock_put(sk); } -- 2.53.0