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=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham 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 E629AC48BDF for ; Fri, 18 Jun 2021 17:37:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C64C560698 for ; Fri, 18 Jun 2021 17:37:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232891AbhFRRjM (ORCPT ); Fri, 18 Jun 2021 13:39:12 -0400 Received: from mo4-p01-ob.smtp.rzone.de ([81.169.146.166]:15078 "EHLO mo4-p01-ob.smtp.rzone.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232482AbhFRRjM (ORCPT ); Fri, 18 Jun 2021 13:39:12 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; t=1624037821; s=strato-dkim-0002; d=hartkopp.net; h=Message-Id:Date:Subject:Cc:To:From:Cc:Date:From:Subject:Sender; bh=WvA82nkklBw0SViN504lD6tM11gS4L/jSSq1mmQNij4=; b=bgnNplGdqnLJfnbqqDymdLetRp+sYmHj8isgV1kIu6QPZC21AvGYjsIK/OAWZDp0uV IUT6195G9tovFzSCdXj9v3UQXXTWSFQb83W8S6zdhBAx3qQkMiucI4mt0O/L6wcGk+nv Yfl5FkzTHbc23HY9DmdWI1AYtKclH/xkZKpqOPiUgyGQCIc8Mibhitnmx2DMe976hB1n d4tSC8qpN3YqOKE7/kxZm1eZORPUrVEyk5VBTRqtzEe3sMPr3/fe8cCvOlS8acW2ZPYe nxlFG7GR7tpvdBkd9iem4UtXUuLdnX5cj4Uz9bfkzh+/kpDssUT8xiaY+qtC/bGVoLAB L4xA== Authentication-Results: strato.com; dkim=none X-RZG-AUTH: ":P2MHfkW8eP4Mre39l357AZT/I7AY/7nT2yrDxb8mjGrp7owjzFK3JbFk1mS0k+8CejudJywjsS7yVw==" X-RZG-CLASS-ID: mo00 Received: from silver.lan by smtp.strato.de (RZmta 47.27.3 DYNA|AUTH) with ESMTPSA id N0b2dax5IHb12us (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256 bits)) (Client did not present a certificate); Fri, 18 Jun 2021 19:37:01 +0200 (CEST) From: Oliver Hartkopp To: linux-can@vger.kernel.org Cc: Oliver Hartkopp Subject: [PATCH] can: gw: syncronize rcu operations before removing gw job entry Date: Fri, 18 Jun 2021 19:36:45 +0200 Message-Id: <20210618173645.2238-1-socketcan@hartkopp.net> X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-can@vger.kernel.org can_can_gw_rcv() is called under RCU protection, so after calling can_rx_unregister, we may call synchronize_rcu in order to wait for any RCU read-side critical sections to finish before removing the kmem_cache entry with the referenced gw job entry. Signed-off-by: Oliver Hartkopp --- net/can/gw.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/can/gw.c b/net/can/gw.c index ba4124805602..d8861e862f15 100644 --- a/net/can/gw.c +++ b/net/can/gw.c @@ -594,10 +594,11 @@ static int cgw_notifier(struct notifier_block *nb, hlist_for_each_entry_safe(gwj, nx, &net->can.cgw_list, list) { if (gwj->src.dev == dev || gwj->dst.dev == dev) { hlist_del(&gwj->list); cgw_unregister_filter(net, gwj); + synchronize_rcu(); kmem_cache_free(cgw_cache, gwj); } } } @@ -1152,10 +1153,11 @@ static void cgw_remove_all_jobs(struct net *net) ASSERT_RTNL(); hlist_for_each_entry_safe(gwj, nx, &net->can.cgw_list, list) { hlist_del(&gwj->list); cgw_unregister_filter(net, gwj); + synchronize_rcu(); kmem_cache_free(cgw_cache, gwj); } } static int cgw_remove_job(struct sk_buff *skb, struct nlmsghdr *nlh, @@ -1220,10 +1222,11 @@ static int cgw_remove_job(struct sk_buff *skb, struct nlmsghdr *nlh, if (memcmp(&gwj->ccgw, &ccgw, sizeof(ccgw))) continue; hlist_del(&gwj->list); cgw_unregister_filter(net, gwj); + synchronize_rcu(); kmem_cache_free(cgw_cache, gwj); err = 0; break; } -- 2.30.2