+From: Sven Eckelmann <sven@narfation.org>
+Date: Fri, 31 Aug 2018 16:56:29 +0200
+Subject: [PATCH] batman-adv: Fix segfault when writing to sysfs elp_interval
+
+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 <sven@narfation.org>
+Acked-by: Marek Lindner <mareklindner@neomailbox.ch>
+
+Origin: upstream, https://git.open-mesh.org/batman-adv.git/commit/848be9859b0109a6e428f92f21f2e660153b1c75
+---
+ 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 ae22db3d6637dde2fcc238826a624ef2d6dbd8f5..a4e6f158de26dea0e8e3fefd5b9aeec3dcd64457 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,