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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,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 5DE1AC5DF60 for ; Fri, 8 Nov 2019 11:52:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 337A02084D for ; Fri, 8 Nov 2019 11:52:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1573213978; bh=ON1L6FHRZCSgyfc+YX7cNsYgDakQmYbouwjMn0KnQBE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=T77vk/6DYz8CvfLDowReCnaBYheOBIRDwY0Q01279A4rKb3hiYWBQI3g7RKL3EZAc r7qzbJYd9vaVICyvlvmt/pI+R5epUYRilqkwlp9xQWrSTR3euiiZSvtxgHBCibXAz9 ZIL4OAR2OGwjqsLzj88/4q8lGrvXf8DiAsgO1Xqo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391616AbfKHLw4 (ORCPT ); Fri, 8 Nov 2019 06:52:56 -0500 Received: from mail.kernel.org ([198.145.29.99]:35102 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2403799AbfKHLq7 (ORCPT ); Fri, 8 Nov 2019 06:46:59 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id E9FE9218AE; Fri, 8 Nov 2019 11:46:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1573213618; bh=ON1L6FHRZCSgyfc+YX7cNsYgDakQmYbouwjMn0KnQBE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=CRnwpEht6byJvfdDH/NiC9BbKN16tUy042TS5yiR+BjCWeoIY8XZ/rRjrGzupZ2ip QDEkkxLF79+y6IVUWL5UToJWG8MH1rXbI6Vsuvrvz3lUah8GbedU+UbC0wDi4qMK9b GPSlAzp7fAXcEYnQbxN4VKCiDEePsKw6S3oqV3GA= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Cong Wang , "David S . Miller" , Sasha Levin , netdev@vger.kernel.org Subject: [PATCH AUTOSEL 4.9 51/64] llc: avoid blocking in llc_sap_close() Date: Fri, 8 Nov 2019 06:45:32 -0500 Message-Id: <20191108114545.15351-51-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191108114545.15351-1-sashal@kernel.org> References: <20191108114545.15351-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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 82d989995d18a..95e5ced4c1339 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 e896a2c53b120..f1e442a39db8d 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