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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,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 04F2DC432C3 for ; Tue, 19 Nov 2019 06:07:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C192020672 for ; Tue, 19 Nov 2019 06:07:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1574143665; bh=J6ZEfStz5DT4isXE9ce7olgvh3mbHLrQijoXZCL5OSk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=f/Y5XXx6kZUrohR4OjO0L35Rpz6h4HKz48ElPf1yTpBntzoVJcXBkApne4F6oxpu+ ju7K9fKGRpffHcUxK4fOknbfjgpNMpqkWbSLjmGcrGeGheBhI6RhAiOpehlWmpvJmP ir2L5N5gfvAfnCrerWbk7DfKgG71x3sUIXKtt2sk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729433AbfKSFcm (ORCPT ); Tue, 19 Nov 2019 00:32:42 -0500 Received: from mail.kernel.org ([198.145.29.99]:53010 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729432AbfKSFck (ORCPT ); Tue, 19 Nov 2019 00:32:40 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 7E76321783; Tue, 19 Nov 2019 05:32:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1574141560; bh=J6ZEfStz5DT4isXE9ce7olgvh3mbHLrQijoXZCL5OSk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=D8l+8V/O2csoIiAZLZd7UJFoCT0yeoupEzFJaAQrWOyw6pASyEiday1mCanwrTbl+ cPSPNl0ZgQ+tzZw2NE7+Cel0wasySaoomTaZbLiVXRC1bBC9V/I+4nahHaG80Z2c21 uzkqKth5F7uIAose8tdsjDmuUbiVHSVs7BTJ5ZdA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Cong Wang , "David S. Miller" , Sasha Levin Subject: [PATCH 4.19 202/422] llc: avoid blocking in llc_sap_close() Date: Tue, 19 Nov 2019 06:16:39 +0100 Message-Id: <20191119051411.667907402@linuxfoundation.org> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191119051400.261610025@linuxfoundation.org> References: <20191119051400.261610025@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Cong Wang [ Upstream commit 9708d2b5b7c648e8e0a40d11e8cea12f6277f33c ] llc_sap_close() is called by llc_sap_put() which could be called in BH context in llc_rcv(). We can't block in BH. There is no reason to block it here, kfree_rcu() should be sufficient. Signed-off-by: Cong Wang Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- include/net/llc.h | 1 + net/llc/llc_core.c | 4 +--- 2 files changed, 2 insertions(+), 3 deletions(-) diff --git a/include/net/llc.h b/include/net/llc.h index 890a87318014d..df282d9b40170 100644 --- a/include/net/llc.h +++ b/include/net/llc.h @@ -66,6 +66,7 @@ struct llc_sap { int sk_count; struct hlist_nulls_head sk_laddr_hash[LLC_SK_LADDR_HASH_ENTRIES]; struct hlist_head sk_dev_hash[LLC_SK_DEV_HASH_ENTRIES]; + struct rcu_head rcu; }; static inline diff --git a/net/llc/llc_core.c b/net/llc/llc_core.c index 260b3dc1b4a2a..64d4bef04e730 100644 --- a/net/llc/llc_core.c +++ b/net/llc/llc_core.c @@ -127,9 +127,7 @@ void llc_sap_close(struct llc_sap *sap) list_del_rcu(&sap->node); spin_unlock_bh(&llc_sap_list_lock); - synchronize_rcu(); - - kfree(sap); + kfree_rcu(sap, rcu); } static struct packet_type llc_packet_type __read_mostly = { -- 2.20.1