1
linux/net/mac80211/debugfs_key.c
Jesper Juhl 520efd1ace mac80211: fix failure to check kmalloc return value in key_key_read
I noticed two small issues in mac80211/debugfs_key.c::key_key_read while
reading through the code. Patch below.

The key_key_read() function returns ssize_t and the value that's actually
returned is the return value of simple_read_from_buffer() which also
returns ssize_t, so let's hold the return value in a ssize_t local
variable rather than a int one.

Also, memory is allocated dynamically with kmalloc() which can fail, but
the return value of kmalloc() is not checked, so we may end up operating
on a null pointer further on. So check for a NULL return and bail out with
-ENOMEM in that case.

Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2010-10-29 14:33:26 -04:00

342 lines
8.7 KiB
C

/*
* Copyright 2003-2005 Devicescape Software, Inc.
* Copyright (c) 2006 Jiri Benc <jbenc@suse.cz>
* Copyright 2007 Johannes Berg <johannes@sipsolutions.net>
*
* 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/kobject.h>
#include <linux/slab.h>
#include "ieee80211_i.h"
#include "key.h"
#include "debugfs.h"
#include "debugfs_key.h"
#define KEY_READ(name, prop, buflen, format_string) \
static ssize_t key_##name##_read(struct file *file, \
char __user *userbuf, \
size_t count, loff_t *ppos) \
{ \
char buf[buflen]; \
struct ieee80211_key *key = file->private_data; \
int res = scnprintf(buf, buflen, format_string, key->prop); \
return simple_read_from_buffer(userbuf, count, ppos, buf, res); \
}
#define KEY_READ_D(name) KEY_READ(name, name, 20, "%d\n")
#define KEY_READ_X(name) KEY_READ(name, name, 20, "0x%x\n")
#define KEY_OPS(name) \
static const struct file_operations key_ ##name## _ops = { \
.read = key_##name##_read, \
.open = mac80211_open_file_generic, \
.llseek = generic_file_llseek, \
}
#define KEY_FILE(name, format) \
KEY_READ_##format(name) \
KEY_OPS(name)
#define KEY_CONF_READ(name, buflen, format_string) \
KEY_READ(conf_##name, conf.name, buflen, format_string)
#define KEY_CONF_READ_D(name) KEY_CONF_READ(name, 20, "%d\n")
#define KEY_CONF_OPS(name) \
static const struct file_operations key_ ##name## _ops = { \
.read = key_conf_##name##_read, \
.open = mac80211_open_file_generic, \
.llseek = generic_file_llseek, \
}
#define KEY_CONF_FILE(name, format) \
KEY_CONF_READ_##format(name) \
KEY_CONF_OPS(name)
KEY_CONF_FILE(keylen, D);
KEY_CONF_FILE(keyidx, D);
KEY_CONF_FILE(hw_key_idx, D);
KEY_FILE(flags, X);
KEY_FILE(tx_rx_count, D);
KEY_READ(ifindex, sdata->name, IFNAMSIZ + 2, "%s\n");
KEY_OPS(ifindex);
static ssize_t key_algorithm_read(struct file *file,
char __user *userbuf,
size_t count, loff_t *ppos)
{
char buf[15];
struct ieee80211_key *key = file->private_data;
u32 c = key->conf.cipher;
sprintf(buf, "%.2x-%.2x-%.2x:%d\n",
c >> 24, (c >> 16) & 0xff, (c >> 8) & 0xff, c & 0xff);
return simple_read_from_buffer(userbuf, count, ppos, buf, strlen(buf));
}
KEY_OPS(algorithm);
static ssize_t key_tx_spec_read(struct file *file, char __user *userbuf,
size_t count, loff_t *ppos)
{
const u8 *tpn;
char buf[20];
int len;
struct ieee80211_key *key = file->private_data;
switch (key->conf.cipher) {
case WLAN_CIPHER_SUITE_WEP40:
case WLAN_CIPHER_SUITE_WEP104:
len = scnprintf(buf, sizeof(buf), "\n");
break;
case WLAN_CIPHER_SUITE_TKIP:
len = scnprintf(buf, sizeof(buf), "%08x %04x\n",
key->u.tkip.tx.iv32,
key->u.tkip.tx.iv16);
break;
case WLAN_CIPHER_SUITE_CCMP:
tpn = key->u.ccmp.tx_pn;
len = scnprintf(buf, sizeof(buf), "%02x%02x%02x%02x%02x%02x\n",
tpn[0], tpn[1], tpn[2], tpn[3], tpn[4], tpn[5]);
break;
case WLAN_CIPHER_SUITE_AES_CMAC:
tpn = key->u.aes_cmac.tx_pn;
len = scnprintf(buf, sizeof(buf), "%02x%02x%02x%02x%02x%02x\n",
tpn[0], tpn[1], tpn[2], tpn[3], tpn[4],
tpn[5]);
break;
default:
return 0;
}
return simple_read_from_buffer(userbuf, count, ppos, buf, len);
}
KEY_OPS(tx_spec);
static ssize_t key_rx_spec_read(struct file *file, char __user *userbuf,
size_t count, loff_t *ppos)
{
struct ieee80211_key *key = file->private_data;
char buf[14*NUM_RX_DATA_QUEUES+1], *p = buf;
int i, len;
const u8 *rpn;
switch (key->conf.cipher) {
case WLAN_CIPHER_SUITE_WEP40:
case WLAN_CIPHER_SUITE_WEP104:
len = scnprintf(buf, sizeof(buf), "\n");
break;
case WLAN_CIPHER_SUITE_TKIP:
for (i = 0; i < NUM_RX_DATA_QUEUES; i++)
p += scnprintf(p, sizeof(buf)+buf-p,
"%08x %04x\n",
key->u.tkip.rx[i].iv32,
key->u.tkip.rx[i].iv16);
len = p - buf;
break;
case WLAN_CIPHER_SUITE_CCMP:
for (i = 0; i < NUM_RX_DATA_QUEUES + 1; i++) {
rpn = key->u.ccmp.rx_pn[i];
p += scnprintf(p, sizeof(buf)+buf-p,
"%02x%02x%02x%02x%02x%02x\n",
rpn[0], rpn[1], rpn[2],
rpn[3], rpn[4], rpn[5]);
}
len = p - buf;
break;
case WLAN_CIPHER_SUITE_AES_CMAC:
rpn = key->u.aes_cmac.rx_pn;
p += scnprintf(p, sizeof(buf)+buf-p,
"%02x%02x%02x%02x%02x%02x\n",
rpn[0], rpn[1], rpn[2],
rpn[3], rpn[4], rpn[5]);
len = p - buf;
break;
default:
return 0;
}
return simple_read_from_buffer(userbuf, count, ppos, buf, len);
}
KEY_OPS(rx_spec);
static ssize_t key_replays_read(struct file *file, char __user *userbuf,
size_t count, loff_t *ppos)
{
struct ieee80211_key *key = file->private_data;
char buf[20];
int len;
switch (key->conf.cipher) {
case WLAN_CIPHER_SUITE_CCMP:
len = scnprintf(buf, sizeof(buf), "%u\n", key->u.ccmp.replays);
break;
case WLAN_CIPHER_SUITE_AES_CMAC:
len = scnprintf(buf, sizeof(buf), "%u\n",
key->u.aes_cmac.replays);
break;
default:
return 0;
}
return simple_read_from_buffer(userbuf, count, ppos, buf, len);
}
KEY_OPS(replays);
static ssize_t key_icverrors_read(struct file *file, char __user *userbuf,
size_t count, loff_t *ppos)
{
struct ieee80211_key *key = file->private_data;
char buf[20];
int len;
switch (key->conf.cipher) {
case WLAN_CIPHER_SUITE_AES_CMAC:
len = scnprintf(buf, sizeof(buf), "%u\n",
key->u.aes_cmac.icverrors);
break;
default:
return 0;
}
return simple_read_from_buffer(userbuf, count, ppos, buf, len);
}
KEY_OPS(icverrors);
static ssize_t key_key_read(struct file *file, char __user *userbuf,
size_t count, loff_t *ppos)
{
struct ieee80211_key *key = file->private_data;
int i, bufsize = 2 * key->conf.keylen + 2;
char *buf = kmalloc(bufsize, GFP_KERNEL);
char *p = buf;
ssize_t res;
if (!buf)
return -ENOMEM;
for (i = 0; i < key->conf.keylen; i++)
p += scnprintf(p, bufsize + buf - p, "%02x", key->conf.key[i]);
p += scnprintf(p, bufsize+buf-p, "\n");
res = simple_read_from_buffer(userbuf, count, ppos, buf, p - buf);
kfree(buf);
return res;
}
KEY_OPS(key);
#define DEBUGFS_ADD(name) \
debugfs_create_file(#name, 0400, key->debugfs.dir, \
key, &key_##name##_ops);
void ieee80211_debugfs_key_add(struct ieee80211_key *key)
{
static int keycount;
char buf[50];
struct sta_info *sta;
if (!key->local->debugfs.keys)
return;
sprintf(buf, "%d", keycount);
key->debugfs.cnt = keycount;
keycount++;
key->debugfs.dir = debugfs_create_dir(buf,
key->local->debugfs.keys);
if (!key->debugfs.dir)
return;
rcu_read_lock();
sta = rcu_dereference(key->sta);
if (sta)
sprintf(buf, "../../stations/%pM", sta->sta.addr);
rcu_read_unlock();
/* using sta as a boolean is fine outside RCU lock */
if (sta)
key->debugfs.stalink =
debugfs_create_symlink("station", key->debugfs.dir, buf);
DEBUGFS_ADD(keylen);
DEBUGFS_ADD(flags);
DEBUGFS_ADD(keyidx);
DEBUGFS_ADD(hw_key_idx);
DEBUGFS_ADD(tx_rx_count);
DEBUGFS_ADD(algorithm);
DEBUGFS_ADD(tx_spec);
DEBUGFS_ADD(rx_spec);
DEBUGFS_ADD(replays);
DEBUGFS_ADD(icverrors);
DEBUGFS_ADD(key);
DEBUGFS_ADD(ifindex);
};
void ieee80211_debugfs_key_remove(struct ieee80211_key *key)
{
if (!key)
return;
debugfs_remove_recursive(key->debugfs.dir);
key->debugfs.dir = NULL;
}
void ieee80211_debugfs_key_add_default(struct ieee80211_sub_if_data *sdata)
{
char buf[50];
struct ieee80211_key *key;
if (!sdata->debugfs.dir)
return;
/* this is running under the key lock */
key = sdata->default_key;
if (key) {
sprintf(buf, "../keys/%d", key->debugfs.cnt);
sdata->debugfs.default_key =
debugfs_create_symlink("default_key",
sdata->debugfs.dir, buf);
} else
ieee80211_debugfs_key_remove_default(sdata);
}
void ieee80211_debugfs_key_remove_default(struct ieee80211_sub_if_data *sdata)
{
if (!sdata)
return;
debugfs_remove(sdata->debugfs.default_key);
sdata->debugfs.default_key = NULL;
}
void ieee80211_debugfs_key_add_mgmt_default(struct ieee80211_sub_if_data *sdata)
{
char buf[50];
struct ieee80211_key *key;
if (!sdata->debugfs.dir)
return;
/* this is running under the key lock */
key = sdata->default_mgmt_key;
if (key) {
sprintf(buf, "../keys/%d", key->debugfs.cnt);
sdata->debugfs.default_mgmt_key =
debugfs_create_symlink("default_mgmt_key",
sdata->debugfs.dir, buf);
} else
ieee80211_debugfs_key_remove_mgmt_default(sdata);
}
void ieee80211_debugfs_key_remove_mgmt_default(struct ieee80211_sub_if_data *sdata)
{
if (!sdata)
return;
debugfs_remove(sdata->debugfs.default_mgmt_key);
sdata->debugfs.default_mgmt_key = NULL;
}
void ieee80211_debugfs_key_sta_del(struct ieee80211_key *key,
struct sta_info *sta)
{
debugfs_remove(key->debugfs.stalink);
key->debugfs.stalink = NULL;
}