From: Simon Wunderlich <sw@simonwunderlich.de>
To: davem@davemloft.net
Cc: netdev@vger.kernel.org, b.a.t.m.a.n@lists.open-mesh.org,
Sven Eckelmann <sven@narfation.org>,
Simon Wunderlich <sw@simonwunderlich.de>
Subject: [B.A.T.M.A.N.] [PATCH 03/11] batman-adv: Fix segfault when writing to sysfs elp_interval
Date: Wed, 19 Sep 2018 14:22:05 +0200 [thread overview]
Message-ID: <20180919122213.23108-4-sw@simonwunderlich.de> (raw)
In-Reply-To: <20180919122213.23108-1-sw@simonwunderlich.de>
From: Sven Eckelmann <sven@narfation.org>
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>
---
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,
--
2.11.0
next prev parent reply other threads:[~2018-09-19 12:22 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-19 12:22 [B.A.T.M.A.N.] [PATCH 00/11] pull request for net: batman-adv 2018-09-19 Simon Wunderlich
2018-09-19 12:22 ` [B.A.T.M.A.N.] [PATCH 01/11] batman-adv: Avoid probe ELP information leak Simon Wunderlich
2018-09-19 12:22 ` [B.A.T.M.A.N.] [PATCH 02/11] batman-adv: Fix segfault when writing to throughput_override Simon Wunderlich
2018-09-19 12:22 ` Simon Wunderlich [this message]
2018-09-19 12:22 ` [B.A.T.M.A.N.] [PATCH 04/11] batman-adv: Prevent duplicated gateway_node entry Simon Wunderlich
2018-09-19 12:22 ` [B.A.T.M.A.N.] [PATCH 05/11] batman-adv: Prevent duplicated nc_node entry Simon Wunderlich
2018-09-19 12:22 ` [B.A.T.M.A.N.] [PATCH 06/11] batman-adv: Prevent duplicated softif_vlan entry Simon Wunderlich
2018-09-19 12:22 ` [B.A.T.M.A.N.] [PATCH 07/11] batman-adv: Prevent duplicated global TT entry Simon Wunderlich
2018-09-19 12:22 ` [B.A.T.M.A.N.] [PATCH 08/11] batman-adv: Prevent duplicated tvlv handler Simon Wunderlich
2018-09-19 12:22 ` [B.A.T.M.A.N.] [PATCH 09/11] batman-adv: fix backbone_gw refcount on queue_work() failure Simon Wunderlich
2018-09-19 12:22 ` [B.A.T.M.A.N.] [PATCH 10/11] batman-adv: fix hardif_neigh " Simon Wunderlich
2018-09-19 12:22 ` [B.A.T.M.A.N.] [PATCH 11/11] batman-adv: Increase version number to 2018.3 Simon Wunderlich
2018-09-20 3:34 ` [B.A.T.M.A.N.] [PATCH 00/11] pull request for net: batman-adv 2018-09-19 David Miller
2018-09-20 8:09 ` Simon Wunderlich
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