From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-23.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E9DF6C48BE0 for ; Tue, 8 Jun 2021 19:13:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D269661380 for ; Tue, 8 Jun 2021 19:13:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238356AbhFHTOr (ORCPT ); Tue, 8 Jun 2021 15:14:47 -0400 Received: from mail.kernel.org ([198.145.29.99]:45766 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235291AbhFHTDt (ORCPT ); Tue, 8 Jun 2021 15:03:49 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id D60A7613C1; Tue, 8 Jun 2021 18:45:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1623177956; bh=Km3k4y4r7QTpjJ911KmV5kWAD7VlX7z81i/NQACShCs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=R5RmuYF06mdo+s4OdUkASIgnhd21xOGKDdm+KCKG3WpkdHTyTh4OZGM3D5qTywSj3 BJnXKMUOjBqLlnWjUfkFojKCzPl5ZuA0BEW9bfdKqyDoapRMs3dWJ2RmMAhplrvg9Q LSZs0Ac/W5N14116Aj0/0RetZ9TXtTvzsiluqkyc= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Matthieu Baerts , Paolo Abeni , Mat Martineau , Jakub Kicinski , Sasha Levin Subject: [PATCH 5.12 024/161] mptcp: fix sk_forward_memory corruption on retransmission Date: Tue, 8 Jun 2021 20:25:54 +0200 Message-Id: <20210608175946.266983139@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210608175945.476074951@linuxfoundation.org> References: <20210608175945.476074951@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Paolo Abeni [ Upstream commit b5941f066b4ca331db225a976dae1d6ca8cf0ae3 ] MPTCP sk_forward_memory handling is a bit special, as such field is protected by the msk socket spin_lock, instead of the plain socket lock. Currently we have a code path updating such field without handling the relevant lock: __mptcp_retrans() -> __mptcp_clean_una_wakeup() Several helpers in __mptcp_clean_una_wakeup() will update sk_forward_alloc, possibly causing such field corruption, as reported by Matthieu. Address the issue providing and using a new variant of blamed function which explicitly acquires the msk spin lock. Fixes: 64b9cea7a0af ("mptcp: fix spurious retransmissions") Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/172 Reported-by: Matthieu Baerts Tested-by: Matthieu Baerts Signed-off-by: Paolo Abeni Signed-off-by: Mat Martineau Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/mptcp/protocol.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 228dd40828c4..225b98821517 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -937,6 +937,10 @@ static void __mptcp_update_wmem(struct sock *sk) { struct mptcp_sock *msk = mptcp_sk(sk); +#ifdef CONFIG_LOCKDEP + WARN_ON_ONCE(!lockdep_is_held(&sk->sk_lock.slock)); +#endif + if (!msk->wmem_reserved) return; @@ -1075,10 +1079,20 @@ out: static void __mptcp_clean_una_wakeup(struct sock *sk) { +#ifdef CONFIG_LOCKDEP + WARN_ON_ONCE(!lockdep_is_held(&sk->sk_lock.slock)); +#endif __mptcp_clean_una(sk); mptcp_write_space(sk); } +static void mptcp_clean_una_wakeup(struct sock *sk) +{ + mptcp_data_lock(sk); + __mptcp_clean_una_wakeup(sk); + mptcp_data_unlock(sk); +} + static void mptcp_enter_memory_pressure(struct sock *sk) { struct mptcp_subflow_context *subflow; @@ -2288,7 +2302,7 @@ static void __mptcp_retrans(struct sock *sk) struct sock *ssk; int ret; - __mptcp_clean_una_wakeup(sk); + mptcp_clean_una_wakeup(sk); dfrag = mptcp_rtx_head(sk); if (!dfrag) { if (mptcp_data_fin_enabled(msk)) { -- 2.30.2