From patchwork Fri Aug 31 14:46:48 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sven Eckelmann X-Patchwork-Id: 17464 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 CE69682F11; Fri, 31 Aug 2018 16:46:57 +0200 (CEST) Authentication-Results: open-mesh.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=narfation.org header.i=@narfation.org header.b="ohdUkGQo"; dkim-atps=neutral Received-SPF: Pass (mailfrom) identity=mailfrom; client-ip=2001:4d88:2000:7::2; helo=v3-1039.vlinux.de; envelope-from=sven@narfation.org; receiver= Received: from v3-1039.vlinux.de (narfation.org [IPv6:2001:4d88:2000:7::2]) by open-mesh.org (Postfix) with ESMTPS id 820BA82F07 for ; Fri, 31 Aug 2018 16:46:55 +0200 (CEST) Received: from sven-desktop.home.narfation.org (p200300C593CD60FD0000000000004065.dip0.t-ipconnect.de [IPv6:2003:c5:93cd:60fd::4065]) by v3-1039.vlinux.de (Postfix) with ESMTPSA id BEDC61100D6; Fri, 31 Aug 2018 16:46:54 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=narfation.org; s=20121; t=1535726815; bh=qdqxr+Bigd8Ig3btIUzXox4ys8qGOesQnfkocALUARA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ohdUkGQo/5c2XkzdXsqtnMcxEo8400HU0CX88t8WCChI7qtQRzzgPVgQoHZ84ZDrW foIBealuWOFfQPUD820ENSHy0oOHXhbuROm0d84r5cCzBen4CU1kSAOOkk9Nu8Xr58 FjqRqQWeQEK3rUzMmHBy1/V0R302QurYCeY0STZ0= From: Sven Eckelmann To: b.a.t.m.a.n@lists.open-mesh.org Date: Fri, 31 Aug 2018 16:46:48 +0200 Message-Id: <20180831144648.24032-2-sven@narfation.org> X-Mailer: git-send-email 2.18.0 In-Reply-To: <20180831144648.24032-1-sven@narfation.org> References: <20180831144648.24032-1-sven@narfation.org> Subject: [B.A.T.M.A.N.] [PATCH maint 2/2] 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 Errors-To: b.a.t.m.a.n-bounces@lists.open-mesh.org Sender: "B.A.T.M.A.N" 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: ec46535b8275 ("batman-adv: Add hard_iface specific sysfs wrapper macros for UINT") Signed-off-by: Sven Eckelmann --- 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 3a76e897..b2e7bb51 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] = "\0"; 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,