From patchwork Mon May 18 17:35:58 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 225862 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, 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 03EC2C433DF for ; Mon, 18 May 2020 17:42:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C989920835 for ; Mon, 18 May 2020 17:42:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1589823751; bh=l7gQ3LDxqyvmZKILg/1bQZEIGSXRweVRKSuXKY7UX0w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=hWle7avzbsa98EBkYPDVqkLD105ofnedmCQWigMLV9rsn8KKeZEgD2BhcGiL3D+Dh xeIa3sydYIVPrRL2H9cCKkLvQFKdnou6N8WemT+mIflOLhgR5E0Sn1+HA1m1okSwHB YFycGMVOkiLxBVzhTokPvrIGFMHbqU9fopBDxShA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729432AbgERRmb (ORCPT ); Mon, 18 May 2020 13:42:31 -0400 Received: from mail.kernel.org ([198.145.29.99]:39492 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729428AbgERRma (ORCPT ); Mon, 18 May 2020 13:42:30 -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 54F3120715; Mon, 18 May 2020 17:42:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1589823748; bh=l7gQ3LDxqyvmZKILg/1bQZEIGSXRweVRKSuXKY7UX0w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=sKAEIc9hsKAfODKuW/wHCoEFeaEV8V7avxwQEMuk1071CNqOi64daedoLuLLiohOP okoGHyQWg5xf4TlJgBhCmMb+BmBMAb1J9uxm0UAIc0lJYgXAQGd0aaH62gluiZQ9/f cFt8L3t+037bBem28Xr0jQEBvoY36bNc4eQEGtn4= 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 4.9 20/90] batman-adv: Fix refcnt leak in batadv_show_throughput_override Date: Mon, 18 May 2020 19:35:58 +0200 Message-Id: <20200518173455.286190110@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200518173450.930655662@linuxfoundation.org> References: <20200518173450.930655662@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 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 @@ -1120,6 +1120,7 @@ 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); }