diff options
author | Sven Eckelmann <sven@narfation.org> | 2018-08-31 16:56:29 +0200 |
---|---|---|
committer | Simon Wunderlich <sw@simonwunderlich.de> | 2018-09-06 13:54:48 +0200 |
commit | a25bab9d723a08bd0bdafb1529faf9094c690b70 (patch) | |
tree | 284b63130f2d9a96cf1cc82d2f7a809805a7afbf /net/batman-adv/sysfs.c | |
parent | b9fd14c20871e6189f635e49b32d7789e430b3c8 (diff) |
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: 0744ff8fa8fa ("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>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
Diffstat (limited to 'net/batman-adv/sysfs.c')
-rw-r--r-- | net/batman-adv/sysfs.c | 25 |
1 files 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, |