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=-9.5 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 DDC0EC677E4 for ; Mon, 8 Oct 2018 15:26:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A08E121526 for ; Mon, 8 Oct 2018 15:26:38 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="CeaKWrMx" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A08E121526 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728311AbeJHWiv (ORCPT ); Mon, 8 Oct 2018 18:38:51 -0400 Received: from mail.kernel.org ([198.145.29.99]:57524 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727794AbeJHWiu (ORCPT ); Mon, 8 Oct 2018 18:38:50 -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 7227F2075E; Mon, 8 Oct 2018 15:26:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1539012395; bh=quSnEnslFpwyPHOf2roEuuOO/21HCHheIlEp1/ZGiD0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=CeaKWrMxHqAUFwTz8MWmqenqf7NjoWSErkjfvmezWQhPA/SU6R49iKT0FMH+g4aoy 9vxAX4L+TVizgSorZpBrRid9B6q5S0MCPq8YDmZiteDmgnJ/3W4kFqLpPcbzoO+dn4 4ZsgYIafGStd0FnO+fSddtpOA/P2d4KeDBCXtcJg= From: Sasha Levin To: stable@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Sven Eckelmann , Simon Wunderlich , Sasha Levin Subject: [PATCH AUTOSEL 4.14 04/32] batman-adv: Fix segfault when writing to sysfs elp_interval Date: Mon, 8 Oct 2018 11:26:01 -0400 Message-Id: <20181008152629.70812-4-sashal@kernel.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20181008152629.70812-1-sashal@kernel.org> References: <20181008152629.70812-1-sashal@kernel.org> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Sven Eckelmann [ Upstream commit a25bab9d723a08bd0bdafb1529faf9094c690b70 ] The per hardif sysfs file "batman_adv/elp_interval" is using the generic functions to store/show uint values. The helper __batadv_store_uint_attr requires the softif net_device as parameter to print the resulting change as info text when the users writes to this file. It uses the helper function batadv_info to add it at the same time to the kernel ring buffer and to the batman-adv debug log (when CONFIG_BATMAN_ADV_DEBUG is enabled). The function batadv_info requires as first parameter the batman-adv softif net_device. This parameter is then used to find the private buffer which contains the debug log for this batman-adv interface. But batadv_store_throughput_override used as first argument the slave net_device. This slave device doesn't have the batadv_priv private data which is access by batadv_info. Writing to this file with CONFIG_BATMAN_ADV_DEBUG enabled can either lead to a segfault or to memory corruption. Fixes: 0744ff8fa8fa ("batman-adv: Add hard_iface specific sysfs wrapper macros for UINT") Signed-off-by: Sven Eckelmann Acked-by: Marek Lindner Signed-off-by: Simon Wunderlich Signed-off-by: Sasha Levin --- net/batman-adv/sysfs.c | 25 +++++++++++++++++-------- 1 file changed, 17 insertions(+), 8 deletions(-) diff --git a/net/batman-adv/sysfs.c b/net/batman-adv/sysfs.c index ec412c5b8697..2ef9b136fc39 100644 --- a/net/batman-adv/sysfs.c +++ b/net/batman-adv/sysfs.c @@ -186,7 +186,8 @@ ssize_t batadv_store_##_name(struct kobject *kobj, \ \ return __batadv_store_uint_attr(buff, count, _min, _max, \ _post_func, attr, \ - &bat_priv->_var, net_dev); \ + &bat_priv->_var, net_dev, \ + NULL); \ } #define BATADV_ATTR_SIF_SHOW_UINT(_name, _var) \ @@ -260,7 +261,9 @@ ssize_t batadv_store_##_name(struct kobject *kobj, \ \ length = __batadv_store_uint_attr(buff, count, _min, _max, \ _post_func, attr, \ - &hard_iface->_var, net_dev); \ + &hard_iface->_var, \ + hard_iface->soft_iface, \ + net_dev); \ \ batadv_hardif_put(hard_iface); \ return length; \ @@ -354,10 +357,12 @@ __batadv_store_bool_attr(char *buff, size_t count, static int batadv_store_uint_attr(const char *buff, size_t count, struct net_device *net_dev, + struct net_device *slave_dev, const char *attr_name, unsigned int min, unsigned int max, atomic_t *attr) { + char ifname[IFNAMSIZ + 3] = ""; unsigned long uint_val; int ret; @@ -383,8 +388,11 @@ static int batadv_store_uint_attr(const char *buff, size_t count, if (atomic_read(attr) == uint_val) return count; - batadv_info(net_dev, "%s: Changing from: %i to: %lu\n", - attr_name, atomic_read(attr), uint_val); + if (slave_dev) + snprintf(ifname, sizeof(ifname), "%s: ", slave_dev->name); + + batadv_info(net_dev, "%s: %sChanging from: %i to: %lu\n", + attr_name, ifname, atomic_read(attr), uint_val); atomic_set(attr, uint_val); return count; @@ -395,12 +403,13 @@ static ssize_t __batadv_store_uint_attr(const char *buff, size_t count, void (*post_func)(struct net_device *), const struct attribute *attr, atomic_t *attr_store, - struct net_device *net_dev) + struct net_device *net_dev, + struct net_device *slave_dev) { int ret; - ret = batadv_store_uint_attr(buff, count, net_dev, attr->name, min, max, - attr_store); + ret = batadv_store_uint_attr(buff, count, net_dev, slave_dev, + attr->name, min, max, attr_store); if (post_func && ret) post_func(net_dev); @@ -569,7 +578,7 @@ static ssize_t batadv_store_gw_sel_class(struct kobject *kobj, return __batadv_store_uint_attr(buff, count, 1, BATADV_TQ_MAX_VALUE, batadv_post_gw_reselect, attr, &bat_priv->gw.sel_class, - bat_priv->soft_iface); + bat_priv->soft_iface, NULL); } static ssize_t batadv_show_gw_bwidth(struct kobject *kobj, -- 2.17.1