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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 663A9C4332F for ; Mon, 7 Feb 2022 11:46:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1387042AbiBGLit (ORCPT ); Mon, 7 Feb 2022 06:38:49 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44578 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1385725AbiBGLcS (ORCPT ); Mon, 7 Feb 2022 06:32:18 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8E7D1C043188; Mon, 7 Feb 2022 03:32:17 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id F2F87B80EBD; Mon, 7 Feb 2022 11:32:15 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 47B2AC004E1; Mon, 7 Feb 2022 11:32:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1644233534; bh=gnZ42VB8luOBpe47zX/EhN1MWbO2bGrsu/FWoeueKY0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=K0ufMjgF8OXHfxvMxouB/e/S7DXY0A+ZlU3BLnyuRSwH+z1njXJ85+wtA1ln7yU// FVgZkFqTMLFIk03kK98hS/EVr7GbPpG+Vi5qswjjG2vamzrh02jdoMml7H6wHnQTGv Pc+6bv62sHMn2qU3j4jnJV/kCo5nvtIvvAIPIB3s= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Paolo Abeni , Mat Martineau , Jakub Kicinski Subject: [PATCH 5.16 042/126] mptcp: fix msk traversal in mptcp_nl_cmd_set_flags() Date: Mon, 7 Feb 2022 12:06:13 +0100 Message-Id: <20220207103805.578390861@linuxfoundation.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220207103804.053675072@linuxfoundation.org> References: <20220207103804.053675072@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: stable@vger.kernel.org From: Paolo Abeni commit 8e9eacad7ec7a9cbf262649ebf1fa6e6f6cc7d82 upstream. The MPTCP endpoint list is under RCU protection, guarded by the pernet spinlock. mptcp_nl_cmd_set_flags() traverses the list without acquiring the spin-lock nor under the RCU critical section. This change addresses the issue performing the lookup and the endpoint update under the pernet spinlock. [The upstream commit had to handle a lookup_by_id variable that is only present in 5.17. This version of the patch removes that variable, so the __lookup_addr() function only handles the lookup as it is implemented in 5.15 and 5.16. It also removes one 'const' keyword to prevent a warning due to differing const-ness in the 5.17 version of addresses_equal().] Fixes: 0f9f696a502e ("mptcp: add set_flags command in PM netlink") Signed-off-by: Paolo Abeni Signed-off-by: Mat Martineau Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman --- net/mptcp/pm_netlink.c | 34 +++++++++++++++++++++++++--------- 1 file changed, 25 insertions(+), 9 deletions(-) --- a/net/mptcp/pm_netlink.c +++ b/net/mptcp/pm_netlink.c @@ -459,6 +459,18 @@ static unsigned int fill_remote_addresse return i; } +static struct mptcp_pm_addr_entry * +__lookup_addr(struct pm_nl_pernet *pernet, struct mptcp_addr_info *info) +{ + struct mptcp_pm_addr_entry *entry; + + list_for_each_entry(entry, &pernet->local_addr_list, list) { + if (addresses_equal(&entry->addr, info, true)) + return entry; + } + return NULL; +} + static void mptcp_pm_create_subflow_or_signal_addr(struct mptcp_sock *msk) { struct sock *sk = (struct sock *)msk; @@ -1725,17 +1737,21 @@ static int mptcp_nl_cmd_set_flags(struct if (addr.flags & MPTCP_PM_ADDR_FLAG_BACKUP) bkup = 1; - list_for_each_entry(entry, &pernet->local_addr_list, list) { - if (addresses_equal(&entry->addr, &addr.addr, true)) { - mptcp_nl_addr_backup(net, &entry->addr, bkup); - - if (bkup) - entry->flags |= MPTCP_PM_ADDR_FLAG_BACKUP; - else - entry->flags &= ~MPTCP_PM_ADDR_FLAG_BACKUP; - } + spin_lock_bh(&pernet->lock); + entry = __lookup_addr(pernet, &addr.addr); + if (!entry) { + spin_unlock_bh(&pernet->lock); + return -EINVAL; } + if (bkup) + entry->flags |= MPTCP_PM_ADDR_FLAG_BACKUP; + else + entry->flags &= ~MPTCP_PM_ADDR_FLAG_BACKUP; + addr = *entry; + spin_unlock_bh(&pernet->lock); + + mptcp_nl_addr_backup(net, &addr.addr, bkup); return 0; }