From patchwork Fri May 1 13:21:17 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 226684 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=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 05112C47254 for ; Fri, 1 May 2020 13:28:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CC1B1216FD for ; Fri, 1 May 2020 13:28:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588339733; bh=tTsw+yYwD3xrXKCecdUfo4izDlAh6sniyrh8KljU0Nc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=0hSlbmGOjE0t3mfFez2DYRrXR16riIUt7Vt4SxWJNBh1kHxZnD/inm3gnyr41tZhP q5YU5dXPPp+dGhU2uD32UsV8pWaR3QTka4PAOkNe+Q0p9PIREVekOkSCKgWfGD7cQz D7oJ08yU1j37BGSYDAA/f2j3lfClp+371On9Qopo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729697AbgEAN2w (ORCPT ); Fri, 1 May 2020 09:28:52 -0400 Received: from mail.kernel.org ([198.145.29.99]:52162 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729158AbgEAN2v (ORCPT ); Fri, 1 May 2020 09:28:51 -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 DD1DE20757; Fri, 1 May 2020 13:28:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588339731; bh=tTsw+yYwD3xrXKCecdUfo4izDlAh6sniyrh8KljU0Nc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=l9bzwdduGath70yNY6H6qOM91yEH+fSl58Ff28SVrGkzlnxD5am97y7RpNVYR0tiK OJ8JV/nn/9CooZU/Ar+HtYQHdbE0gTL/7ffN2ReBA9qmT+MWU6vH5UVE5T3ESs9l8D /hy25I9RRkT0uYYXUsixcKUCczZLXCcRSBd5HE3k= 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 4.9 23/80] net: netrom: Fix potential nr_neigh refcnt leak in nr_add_node Date: Fri, 1 May 2020 15:21:17 +0200 Message-Id: <20200501131521.948479586@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200501131513.810761598@linuxfoundation.org> References: <20200501131513.810761598@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 @@ -199,6 +199,7 @@ 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);