From patchwork Tue Apr 28 18:23:50 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "gregkh@linuxfoundation.org" X-Patchwork-Id: 226733 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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, 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 2FD01C83007 for ; Tue, 28 Apr 2020 19:00:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 01F0D206A1 for ; Tue, 28 Apr 2020 19:00:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588100412; bh=N/8ImIDdPOEXmtj/+HjjuFy7WgAl9RTHoLobDrIcL0s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=nws+10547Aqkj1EWS6qhSFYbn7yEqZmYFQ5T38ECbqPfUa+0LGoYumd82452aPZJ8 nw78VXouoM+QcHB+71HGlFIlgnlxFtDO84uu4CXTuxcarvJBwk71qUN6FzcKDTv3Yx anb+JxaBEBW3KLKLhf49Gk4fTD6Sc/xX86DrJ4Ag= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728606AbgD1S1w (ORCPT ); Tue, 28 Apr 2020 14:27:52 -0400 Received: from mail.kernel.org ([198.145.29.99]:40204 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729043AbgD1S1v (ORCPT ); Tue, 28 Apr 2020 14:27:51 -0400 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 99FC920730; Tue, 28 Apr 2020 18:27:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588098471; bh=N/8ImIDdPOEXmtj/+HjjuFy7WgAl9RTHoLobDrIcL0s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=i9jltwizaaQ9dqgjYnSBa3l6RhMRiLu8VZqKFcRgled4L+f5BMUYDwaEC3+aWMiMf WKc0RJw/FhpL3PwAljHVBAH+ONlSx4EenTecVaHkoCABun4c2WDMz5uBYRUg96V2gw L4sYaJL8HSJoXeq8c7TD0ruFSDtSGbRxzlBpxC8I= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Xiyu Yang , Xin Tan , "David S. Miller" Subject: [PATCH 5.6 054/167] net: netrom: Fix potential nr_neigh refcnt leak in nr_add_node Date: Tue, 28 Apr 2020 20:23:50 +0200 Message-Id: <20200428182231.824760923@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200428182225.451225420@linuxfoundation.org> References: <20200428182225.451225420@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Xiyu Yang [ Upstream commit d03f228470a8c0a22b774d1f8d47071e0de4f6dd ] nr_add_node() invokes nr_neigh_get_dev(), which returns a local reference of the nr_neigh object to "nr_neigh" with increased refcnt. When nr_add_node() returns, "nr_neigh" becomes invalid, so the refcount should be decreased to keep refcount balanced. The issue happens in one normal path of nr_add_node(), which forgets to decrease the refcnt increased by nr_neigh_get_dev() and causes a refcnt leak. It should decrease the refcnt before the function returns like other normal paths do. Fix this issue by calling nr_neigh_put() before the nr_add_node() returns. Signed-off-by: Xiyu Yang Signed-off-by: Xin Tan Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/netrom/nr_route.c | 1 + 1 file changed, 1 insertion(+) --- a/net/netrom/nr_route.c +++ b/net/netrom/nr_route.c @@ -208,6 +208,7 @@ static int __must_check nr_add_node(ax25 /* refcount initialized at 1 */ spin_unlock_bh(&nr_node_list_lock); + nr_neigh_put(nr_neigh); return 0; } nr_node_lock(nr_node);