From patchwork Wed Sep 19 12:22:05 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Simon Wunderlich X-Patchwork-Id: 17486 X-Patchwork-Delegate: sw@simonwunderlich.de Return-Path: X-Original-To: patchwork@open-mesh.org Delivered-To: patchwork@open-mesh.org Received: from open-mesh.org (localhost [IPv6:::1]) by open-mesh.org (Postfix) with ESMTP id 9D33582FD8; Wed, 19 Sep 2018 14:22:25 +0200 (CEST) Received-SPF: Pass (mailfrom) identity=mailfrom; client-ip=2001:4d88:2000:24::c0de; helo=mail.mail.packetmixer.de; envelope-from=sw@simonwunderlich.de; receiver= Received: from mail.mail.packetmixer.de (packetmixer.de [IPv6:2001:4d88:2000:24::c0de]) by open-mesh.org (Postfix) with ESMTPS id 10A488237F for ; Wed, 19 Sep 2018 14:22:17 +0200 (CEST) Received: from kero.packetmixer.de (p200300C593D42E00B540A3BB6637942E.dip0.t-ipconnect.de [IPv6:2003:c5:93d4:2e00:b540:a3bb:6637:942e]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.mail.packetmixer.de (Postfix) with ESMTPSA id 7D91A62055; Wed, 19 Sep 2018 14:22:16 +0200 (CEST) From: Simon Wunderlich To: davem@davemloft.net Date: Wed, 19 Sep 2018 14:22:05 +0200 Message-Id: <20180919122213.23108-4-sw@simonwunderlich.de> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20180919122213.23108-1-sw@simonwunderlich.de> References: <20180919122213.23108-1-sw@simonwunderlich.de> Subject: [B.A.T.M.A.N.] [PATCH 03/11] batman-adv: Fix segfault when writing to sysfs elp_interval X-BeenThere: b.a.t.m.a.n@lists.open-mesh.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: The list for a Better Approach To Mobile Ad-hoc Networking List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: The list for a Better Approach To Mobile Ad-hoc Networking Cc: netdev@vger.kernel.org, b.a.t.m.a.n@lists.open-mesh.org Errors-To: b.a.t.m.a.n-bounces@lists.open-mesh.org Sender: "B.A.T.M.A.N" From: Sven Eckelmann 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 --- 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 3a76e8970c02..09427fc6494a 100644 --- a/net/batman-adv/sysfs.c +++ b/net/batman-adv/sysfs.c @@ -188,7 +188,8 @@ 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) \ @@ -262,7 +263,9 @@ 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; \ @@ -356,10 +359,12 @@ __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; @@ -385,8 +390,11 @@ 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; @@ -397,12 +405,13 @@ 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); @@ -571,7 +580,7 @@ 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,