linux/net/mac80211/ieee80211_rate.c
Cyrill Gorcunov 20880e8936 NET: mac80211: fix inappropriate memory freeing
Fix inappropriate memory freeing in case of requested rate_control_ops was
not found.  In this case the list head entity is going to be accidentally
wasted.

Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
Acked-by: Michael Wu <flamingice@sourmilk.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2007-12-19 16:43:47 -08:00

200 lines
4.3 KiB
C

/*
* Copyright 2002-2005, Instant802 Networks, Inc.
* Copyright 2005-2006, Devicescape Software, Inc.
* Copyright (c) 2006 Jiri Benc <jbenc@suse.cz>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/kernel.h>
#include <linux/rtnetlink.h>
#include "ieee80211_rate.h"
#include "ieee80211_i.h"
struct rate_control_alg {
struct list_head list;
struct rate_control_ops *ops;
};
static LIST_HEAD(rate_ctrl_algs);
static DEFINE_MUTEX(rate_ctrl_mutex);
int ieee80211_rate_control_register(struct rate_control_ops *ops)
{
struct rate_control_alg *alg;
if (!ops->name)
return -EINVAL;
mutex_lock(&rate_ctrl_mutex);
list_for_each_entry(alg, &rate_ctrl_algs, list) {
if (!strcmp(alg->ops->name, ops->name)) {
/* don't register an algorithm twice */
WARN_ON(1);
mutex_unlock(&rate_ctrl_mutex);
return -EALREADY;
}
}
alg = kzalloc(sizeof(*alg), GFP_KERNEL);
if (alg == NULL) {
mutex_unlock(&rate_ctrl_mutex);
return -ENOMEM;
}
alg->ops = ops;
list_add_tail(&alg->list, &rate_ctrl_algs);
mutex_unlock(&rate_ctrl_mutex);
return 0;
}
EXPORT_SYMBOL(ieee80211_rate_control_register);
void ieee80211_rate_control_unregister(struct rate_control_ops *ops)
{
struct rate_control_alg *alg;
mutex_lock(&rate_ctrl_mutex);
list_for_each_entry(alg, &rate_ctrl_algs, list) {
if (alg->ops == ops) {
list_del(&alg->list);
kfree(alg);
break;
}
}
mutex_unlock(&rate_ctrl_mutex);
}
EXPORT_SYMBOL(ieee80211_rate_control_unregister);
static struct rate_control_ops *
ieee80211_try_rate_control_ops_get(const char *name)
{
struct rate_control_alg *alg;
struct rate_control_ops *ops = NULL;
if (!name)
return NULL;
mutex_lock(&rate_ctrl_mutex);
list_for_each_entry(alg, &rate_ctrl_algs, list) {
if (!strcmp(alg->ops->name, name))
if (try_module_get(alg->ops->module)) {
ops = alg->ops;
break;
}
}
mutex_unlock(&rate_ctrl_mutex);
return ops;
}
/* Get the rate control algorithm. If `name' is NULL, get the first
* available algorithm. */
static struct rate_control_ops *
ieee80211_rate_control_ops_get(const char *name)
{
struct rate_control_ops *ops;
if (!name)
name = "simple";
ops = ieee80211_try_rate_control_ops_get(name);
if (!ops) {
request_module("rc80211_%s", name);
ops = ieee80211_try_rate_control_ops_get(name);
}
return ops;
}
static void ieee80211_rate_control_ops_put(struct rate_control_ops *ops)
{
module_put(ops->module);
}
struct rate_control_ref *rate_control_alloc(const char *name,
struct ieee80211_local *local)
{
struct rate_control_ref *ref;
ref = kmalloc(sizeof(struct rate_control_ref), GFP_KERNEL);
if (!ref)
goto fail_ref;
kref_init(&ref->kref);
ref->ops = ieee80211_rate_control_ops_get(name);
if (!ref->ops)
goto fail_ops;
ref->priv = ref->ops->alloc(local);
if (!ref->priv)
goto fail_priv;
return ref;
fail_priv:
ieee80211_rate_control_ops_put(ref->ops);
fail_ops:
kfree(ref);
fail_ref:
return NULL;
}
static void rate_control_release(struct kref *kref)
{
struct rate_control_ref *ctrl_ref;
ctrl_ref = container_of(kref, struct rate_control_ref, kref);
ctrl_ref->ops->free(ctrl_ref->priv);
ieee80211_rate_control_ops_put(ctrl_ref->ops);
kfree(ctrl_ref);
}
struct rate_control_ref *rate_control_get(struct rate_control_ref *ref)
{
kref_get(&ref->kref);
return ref;
}
void rate_control_put(struct rate_control_ref *ref)
{
kref_put(&ref->kref, rate_control_release);
}
int ieee80211_init_rate_ctrl_alg(struct ieee80211_local *local,
const char *name)
{
struct rate_control_ref *ref, *old;
ASSERT_RTNL();
if (local->open_count || netif_running(local->mdev))
return -EBUSY;
ref = rate_control_alloc(name, local);
if (!ref) {
printk(KERN_WARNING "%s: Failed to select rate control "
"algorithm\n", wiphy_name(local->hw.wiphy));
return -ENOENT;
}
old = local->rate_ctrl;
local->rate_ctrl = ref;
if (old) {
rate_control_put(old);
sta_info_flush(local, NULL);
}
printk(KERN_DEBUG "%s: Selected rate control "
"algorithm '%s'\n", wiphy_name(local->hw.wiphy),
ref->ops->name);
return 0;
}
void rate_control_deinitialize(struct ieee80211_local *local)
{
struct rate_control_ref *ref;
ref = local->rate_ctrl;
local->rate_ctrl = NULL;
rate_control_put(ref);
}