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=-9.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 BC3B5C46475 for ; Thu, 25 Oct 2018 14:15:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 818C82147A for ; Thu, 25 Oct 2018 14:15:01 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="DFRth27l" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 818C82147A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728736AbeJYWrz (ORCPT ); Thu, 25 Oct 2018 18:47:55 -0400 Received: from mail.kernel.org ([198.145.29.99]:56134 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728704AbeJYWrx (ORCPT ); Thu, 25 Oct 2018 18:47:53 -0400 Received: from sasha-vm.mshome.net (unknown [167.98.65.38]) (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 A3BAE20848; Thu, 25 Oct 2018 14:14:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1540476897; bh=s8WLDJ7qM2OAUOJ9g91MXT/XYSWvOnHUBQyz9s45d9I=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=DFRth27lykv5MsdJquy1zL7z1UARBU7aOgt8s8sUONpfMqSvIMiv+/X1ErrMDihkY eqZgk+o6C5AvrT+7Oj/LZuVEgISunDjZBiTWamayUxFLKydbcPOwKm9ic2filNXIbp gtAK5XOArttaBhvZSyxv7TQRQo35JAzHnMErug6U= From: Sasha Levin To: stable@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Bob Peterson , "David S . Miller" , Sasha Levin Subject: [PATCH AUTOSEL 4.9 21/98] tipc: Fix tipc_sk_reinit handling of -EAGAIN Date: Thu, 25 Oct 2018 10:13:06 -0400 Message-Id: <20181025141423.213774-21-sashal@kernel.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20181025141423.213774-1-sashal@kernel.org> References: <20181025141423.213774-1-sashal@kernel.org> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Bob Peterson [ Upstream commit 6c7e983b220f89e03286dc70a41c7ef3a8b409df ] In 9dbbfb0ab6680c6a85609041011484e6658e7d3c function tipc_sk_reinit had additional logic added to loop in the event that function rhashtable_walk_next() returned -EAGAIN. No worries. However, if rhashtable_walk_start returns -EAGAIN, it does "continue", and therefore skips the call to rhashtable_walk_stop(). That has the effect of calling rcu_read_lock() without its paired call to rcu_read_unlock(). Since rcu_read_lock() may be nested, the problem may not be apparent for a while, especially since resize events may be rare. But the comments to rhashtable_walk_start() state: * ...Note that we take the RCU lock in all * cases including when we return an error. So you must always call * rhashtable_walk_stop to clean up. This patch replaces the continue with a goto and label to ensure a matching call to rhashtable_walk_stop(). Signed-off-by: Bob Peterson Acked-by: Herbert Xu Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/tipc/socket.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/net/tipc/socket.c b/net/tipc/socket.c index 25bc5c30d7fb..9d3f047305ce 100644 --- a/net/tipc/socket.c +++ b/net/tipc/socket.c @@ -2277,8 +2277,8 @@ void tipc_sk_reinit(struct net *net) do { tsk = ERR_PTR(rhashtable_walk_start(&iter)); - if (tsk) - continue; + if (IS_ERR(tsk)) + goto walk_stop; while ((tsk = rhashtable_walk_next(&iter)) && !IS_ERR(tsk)) { spin_lock_bh(&tsk->sk.sk_lock.slock); @@ -2287,7 +2287,7 @@ void tipc_sk_reinit(struct net *net) msg_set_orignode(msg, tn->own_addr); spin_unlock_bh(&tsk->sk.sk_lock.slock); } - +walk_stop: rhashtable_walk_stop(&iter); } while (tsk == ERR_PTR(-EAGAIN)); } -- 2.17.1