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=-6.9 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 2ADCBCA90AF for ; Wed, 13 May 2020 09:47:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E4B2C20769 for ; Wed, 13 May 2020 09:47:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1589363224; bh=JqvLFulQJvacUXzq45/Z6hDpklPx4qQiKdxm51xAiRM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=RrTsMb0tKMOx+9ZX/j/6F3270b+W90BR43D4vX9z5QOdEAf8oHkNpcfp/1FFhhuJq rMyDID6BbXkzHLsijD6EPx+HM/xJaHU+ovLWFPa3VDftfJyASWZn4bhnTWA1to2sZ6 sA6TNUx8wqreOdZiGpmbncpXtKqStNDsllrX6ul4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732772AbgEMJrD (ORCPT ); Wed, 13 May 2020 05:47:03 -0400 Received: from mail.kernel.org ([198.145.29.99]:44522 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732756AbgEMJq6 (ORCPT ); Wed, 13 May 2020 05:46:58 -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 A4B4E206F5; Wed, 13 May 2020 09:46:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1589363218; bh=JqvLFulQJvacUXzq45/Z6hDpklPx4qQiKdxm51xAiRM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Nu0+EsBjOXl+Ijm5ezujfm8NwHdqyN6/bp5RMqwPD0vFJDhnugBuAM7OyAbfIOOo8 D9pcH/QeFVYHMQONfgZcpZqyBwj/5Kj9DX7eSGCG9wy7zIWcRLTG/KH6Se7cHiBNDU AHolpYOJA8EwH6Dtx6G0porHq5EEYRdCyPM7ndZs= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Xiyu Yang , Xin Tan , Sven Eckelmann , Simon Wunderlich Subject: [PATCH 4.19 34/48] batman-adv: Fix refcnt leak in batadv_show_throughput_override Date: Wed, 13 May 2020 11:45:00 +0200 Message-Id: <20200513094400.382531314@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200513094351.100352960@linuxfoundation.org> References: <20200513094351.100352960@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Xiyu Yang commit f872de8185acf1b48b954ba5bd8f9bc0a0d14016 upstream. batadv_show_throughput_override() invokes batadv_hardif_get_by_netdev(), which gets a batadv_hard_iface object from net_dev with increased refcnt and its reference is assigned to a local pointer 'hard_iface'. When batadv_show_throughput_override() returns, "hard_iface" becomes invalid, so the refcount should be decreased to keep refcount balanced. The issue happens in the normal path of batadv_show_throughput_override(), which forgets to decrease the refcnt increased by batadv_hardif_get_by_netdev() before the function returns, causing a refcnt leak. Fix this issue by calling batadv_hardif_put() before the batadv_show_throughput_override() returns in the normal path. Fixes: 0b5ecc6811bd ("batman-adv: add throughput override attribute to hard_ifaces") Signed-off-by: Xiyu Yang Signed-off-by: Xin Tan Signed-off-by: Sven Eckelmann Signed-off-by: Simon Wunderlich Signed-off-by: Greg Kroah-Hartman --- net/batman-adv/sysfs.c | 1 + 1 file changed, 1 insertion(+) --- a/net/batman-adv/sysfs.c +++ b/net/batman-adv/sysfs.c @@ -1126,6 +1126,7 @@ static ssize_t batadv_show_throughput_ov tp_override = atomic_read(&hard_iface->bat_v.throughput_override); + batadv_hardif_put(hard_iface); return sprintf(buff, "%u.%u MBit\n", tp_override / 10, tp_override % 10); }