mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-27 19:29:37 +00:00
![Florian Westphal](/assets/img/avatar_default.png)
syzbot reports:
detected buffer overflow in strlen
[..]
Call Trace:
strlen include/linux/string.h:325 [inline]
strlcpy include/linux/string.h:348 [inline]
xt_rateest_tg_checkentry+0x2a5/0x6b0 net/netfilter/xt_RATEEST.c:143
strlcpy assumes src is a c-string. Check info->name before its used.
Reported-by: syzbot+e86f7c428c8c50db65b4@syzkaller.appspotmail.com
Fixes: 5859034d7e
("[NETFILTER]: x_tables: add RATEEST target")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
232 lines
5.5 KiB
C
232 lines
5.5 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/*
|
|
* (C) 2007 Patrick McHardy <kaber@trash.net>
|
|
*/
|
|
#include <linux/module.h>
|
|
#include <linux/skbuff.h>
|
|
#include <linux/gen_stats.h>
|
|
#include <linux/jhash.h>
|
|
#include <linux/rtnetlink.h>
|
|
#include <linux/random.h>
|
|
#include <linux/slab.h>
|
|
#include <net/gen_stats.h>
|
|
#include <net/netlink.h>
|
|
#include <net/netns/generic.h>
|
|
|
|
#include <linux/netfilter/x_tables.h>
|
|
#include <linux/netfilter/xt_RATEEST.h>
|
|
#include <net/netfilter/xt_rateest.h>
|
|
|
|
#define RATEEST_HSIZE 16
|
|
|
|
struct xt_rateest_net {
|
|
struct mutex hash_lock;
|
|
struct hlist_head hash[RATEEST_HSIZE];
|
|
};
|
|
|
|
static unsigned int xt_rateest_id;
|
|
|
|
static unsigned int jhash_rnd __read_mostly;
|
|
|
|
static unsigned int xt_rateest_hash(const char *name)
|
|
{
|
|
return jhash(name, sizeof_field(struct xt_rateest, name), jhash_rnd) &
|
|
(RATEEST_HSIZE - 1);
|
|
}
|
|
|
|
static void xt_rateest_hash_insert(struct xt_rateest_net *xn,
|
|
struct xt_rateest *est)
|
|
{
|
|
unsigned int h;
|
|
|
|
h = xt_rateest_hash(est->name);
|
|
hlist_add_head(&est->list, &xn->hash[h]);
|
|
}
|
|
|
|
static struct xt_rateest *__xt_rateest_lookup(struct xt_rateest_net *xn,
|
|
const char *name)
|
|
{
|
|
struct xt_rateest *est;
|
|
unsigned int h;
|
|
|
|
h = xt_rateest_hash(name);
|
|
hlist_for_each_entry(est, &xn->hash[h], list) {
|
|
if (strcmp(est->name, name) == 0) {
|
|
est->refcnt++;
|
|
return est;
|
|
}
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
struct xt_rateest *xt_rateest_lookup(struct net *net, const char *name)
|
|
{
|
|
struct xt_rateest_net *xn = net_generic(net, xt_rateest_id);
|
|
struct xt_rateest *est;
|
|
|
|
mutex_lock(&xn->hash_lock);
|
|
est = __xt_rateest_lookup(xn, name);
|
|
mutex_unlock(&xn->hash_lock);
|
|
return est;
|
|
}
|
|
EXPORT_SYMBOL_GPL(xt_rateest_lookup);
|
|
|
|
void xt_rateest_put(struct net *net, struct xt_rateest *est)
|
|
{
|
|
struct xt_rateest_net *xn = net_generic(net, xt_rateest_id);
|
|
|
|
mutex_lock(&xn->hash_lock);
|
|
if (--est->refcnt == 0) {
|
|
hlist_del(&est->list);
|
|
gen_kill_estimator(&est->rate_est);
|
|
/*
|
|
* gen_estimator est_timer() might access est->lock or bstats,
|
|
* wait a RCU grace period before freeing 'est'
|
|
*/
|
|
kfree_rcu(est, rcu);
|
|
}
|
|
mutex_unlock(&xn->hash_lock);
|
|
}
|
|
EXPORT_SYMBOL_GPL(xt_rateest_put);
|
|
|
|
static unsigned int
|
|
xt_rateest_tg(struct sk_buff *skb, const struct xt_action_param *par)
|
|
{
|
|
const struct xt_rateest_target_info *info = par->targinfo;
|
|
struct gnet_stats_basic_packed *stats = &info->est->bstats;
|
|
|
|
spin_lock_bh(&info->est->lock);
|
|
stats->bytes += skb->len;
|
|
stats->packets++;
|
|
spin_unlock_bh(&info->est->lock);
|
|
|
|
return XT_CONTINUE;
|
|
}
|
|
|
|
static int xt_rateest_tg_checkentry(const struct xt_tgchk_param *par)
|
|
{
|
|
struct xt_rateest_net *xn = net_generic(par->net, xt_rateest_id);
|
|
struct xt_rateest_target_info *info = par->targinfo;
|
|
struct xt_rateest *est;
|
|
struct {
|
|
struct nlattr opt;
|
|
struct gnet_estimator est;
|
|
} cfg;
|
|
int ret;
|
|
|
|
if (strnlen(info->name, sizeof(est->name)) >= sizeof(est->name))
|
|
return -ENAMETOOLONG;
|
|
|
|
net_get_random_once(&jhash_rnd, sizeof(jhash_rnd));
|
|
|
|
mutex_lock(&xn->hash_lock);
|
|
est = __xt_rateest_lookup(xn, info->name);
|
|
if (est) {
|
|
mutex_unlock(&xn->hash_lock);
|
|
/*
|
|
* If estimator parameters are specified, they must match the
|
|
* existing estimator.
|
|
*/
|
|
if ((!info->interval && !info->ewma_log) ||
|
|
(info->interval != est->params.interval ||
|
|
info->ewma_log != est->params.ewma_log)) {
|
|
xt_rateest_put(par->net, est);
|
|
return -EINVAL;
|
|
}
|
|
info->est = est;
|
|
return 0;
|
|
}
|
|
|
|
ret = -ENOMEM;
|
|
est = kzalloc(sizeof(*est), GFP_KERNEL);
|
|
if (!est)
|
|
goto err1;
|
|
|
|
strlcpy(est->name, info->name, sizeof(est->name));
|
|
spin_lock_init(&est->lock);
|
|
est->refcnt = 1;
|
|
est->params.interval = info->interval;
|
|
est->params.ewma_log = info->ewma_log;
|
|
|
|
cfg.opt.nla_len = nla_attr_size(sizeof(cfg.est));
|
|
cfg.opt.nla_type = TCA_STATS_RATE_EST;
|
|
cfg.est.interval = info->interval;
|
|
cfg.est.ewma_log = info->ewma_log;
|
|
|
|
ret = gen_new_estimator(&est->bstats, NULL, &est->rate_est,
|
|
&est->lock, NULL, &cfg.opt);
|
|
if (ret < 0)
|
|
goto err2;
|
|
|
|
info->est = est;
|
|
xt_rateest_hash_insert(xn, est);
|
|
mutex_unlock(&xn->hash_lock);
|
|
return 0;
|
|
|
|
err2:
|
|
kfree(est);
|
|
err1:
|
|
mutex_unlock(&xn->hash_lock);
|
|
return ret;
|
|
}
|
|
|
|
static void xt_rateest_tg_destroy(const struct xt_tgdtor_param *par)
|
|
{
|
|
struct xt_rateest_target_info *info = par->targinfo;
|
|
|
|
xt_rateest_put(par->net, info->est);
|
|
}
|
|
|
|
static struct xt_target xt_rateest_tg_reg __read_mostly = {
|
|
.name = "RATEEST",
|
|
.revision = 0,
|
|
.family = NFPROTO_UNSPEC,
|
|
.target = xt_rateest_tg,
|
|
.checkentry = xt_rateest_tg_checkentry,
|
|
.destroy = xt_rateest_tg_destroy,
|
|
.targetsize = sizeof(struct xt_rateest_target_info),
|
|
.usersize = offsetof(struct xt_rateest_target_info, est),
|
|
.me = THIS_MODULE,
|
|
};
|
|
|
|
static __net_init int xt_rateest_net_init(struct net *net)
|
|
{
|
|
struct xt_rateest_net *xn = net_generic(net, xt_rateest_id);
|
|
int i;
|
|
|
|
mutex_init(&xn->hash_lock);
|
|
for (i = 0; i < ARRAY_SIZE(xn->hash); i++)
|
|
INIT_HLIST_HEAD(&xn->hash[i]);
|
|
return 0;
|
|
}
|
|
|
|
static struct pernet_operations xt_rateest_net_ops = {
|
|
.init = xt_rateest_net_init,
|
|
.id = &xt_rateest_id,
|
|
.size = sizeof(struct xt_rateest_net),
|
|
};
|
|
|
|
static int __init xt_rateest_tg_init(void)
|
|
{
|
|
int err = register_pernet_subsys(&xt_rateest_net_ops);
|
|
|
|
if (err)
|
|
return err;
|
|
return xt_register_target(&xt_rateest_tg_reg);
|
|
}
|
|
|
|
static void __exit xt_rateest_tg_fini(void)
|
|
{
|
|
xt_unregister_target(&xt_rateest_tg_reg);
|
|
unregister_pernet_subsys(&xt_rateest_net_ops);
|
|
}
|
|
|
|
|
|
MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_DESCRIPTION("Xtables: packet rate estimator");
|
|
MODULE_ALIAS("ipt_RATEEST");
|
|
MODULE_ALIAS("ip6t_RATEEST");
|
|
module_init(xt_rateest_tg_init);
|
|
module_exit(xt_rateest_tg_fini);
|