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 6FE5CC433E3 for ; Thu, 14 May 2020 18:59:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3E14720727 for ; Thu, 14 May 2020 18:59:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1589482753; bh=GiW5jJVTAQv8wgCT0GNmmSwq7wuYgS+rkA7XRNs5qCE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=r4KF0wnERGVWXM9m60eSsAknF7rQF6/dte8Zhc3VYa+ZQmtgDRogSmYZu3M1JUail F6o82JxSBo0MdeZP91uHBgct578JvrR/b17MhXuXY/1wlrkO8eYL9lhLdKPq79aQKH X4s4c3LOyLBkzIq2PVDwwBz2+3kH16KxuGUKOKEg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729640AbgENS4P (ORCPT ); Thu, 14 May 2020 14:56:15 -0400 Received: from mail.kernel.org ([198.145.29.99]:56746 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729536AbgENSz5 (ORCPT ); Thu, 14 May 2020 14:55:57 -0400 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 EB78D2076A; Thu, 14 May 2020 18:55:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1589482556; bh=GiW5jJVTAQv8wgCT0GNmmSwq7wuYgS+rkA7XRNs5qCE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=h0kLCR/GOyVH4F++9DtbyjwpyATpdpMY/eP943uLI+/5KkRFczogYG2cMLolnzDZz SzZ8OoOStYYmql/Cctm3cZXrMMHrTGKZiWKTgrMQDbWZ8D++YFc+68Yrq3Dh7BIKiS UbqBiiVdB0V4fc5LyIhmDDHYj+DXFne/715Hodqk= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Xiyu Yang , Xin Tan , Sven Eckelmann , Simon Wunderlich , Sasha Levin , b.a.t.m.a.n@lists.open-mesh.org, netdev@vger.kernel.org Subject: [PATCH AUTOSEL 4.9 05/27] batman-adv: Fix refcnt leak in batadv_show_throughput_override Date: Thu, 14 May 2020 14:55:28 -0400 Message-Id: <20200514185550.21462-5-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200514185550.21462-1-sashal@kernel.org> References: <20200514185550.21462-1-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: Xiyu Yang [ Upstream commit f872de8185acf1b48b954ba5bd8f9bc0a0d14016 ] 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: Sasha Levin --- net/batman-adv/sysfs.c | 1 + 1 file changed, 1 insertion(+) diff --git a/net/batman-adv/sysfs.c b/net/batman-adv/sysfs.c index 31d7e239a1fd6..d3fb5396f9473 100644 --- a/net/batman-adv/sysfs.c +++ b/net/batman-adv/sysfs.c @@ -1120,6 +1120,7 @@ static ssize_t batadv_show_throughput_override(struct kobject *kobj, 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); } -- 2.20.1