[PATCH 3.19 177/177] Revert "netfilter: xt_recent: relax ip_pkt_list_tot restrictions"

Greg Kroah-Hartman
2015-03-16T15:19:36Z

From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This reverts commit abc86d0f99242b7f142b7cb8f90e30081dd3c256 as it is
broken in 3.19 and is easier to revert here than try to fix it.

Reported-by: Florian Westphal <fw@strlen.de
Reported-by: David Miller <davem@redhat.com>
Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org

---
net/netfilter/xt_recent.c | 64 ++++++++++++----------------------------------
1 file changed, 17 insertions(+), 47 deletions(-)

--- a/net/netfilter/xt_recent.c
+++ b/net/netfilter/xt_recent.c
@@ -43,29 +43,25 @@ MODULE_LICENSE("GPL");
MODULE_ALIAS("ipt_recent");
MODULE_ALIAS("ip6t_recent");

-static unsigned int ip_list_tot __read_mostly = 100;
-static unsigned int ip_list_hash_size __read_mostly;
-static unsigned int ip_list_perms __read_mostly = 0644;
-static unsigned int ip_list_uid __read_mostly;
-static unsigned int ip_list_gid __read_mostly;
+static unsigned int ip_list_tot = 100;
+static unsigned int ip_pkt_list_tot = 20;
+static unsigned int ip_list_hash_size = 0;
+static unsigned int ip_list_perms = 0644;
+static unsigned int ip_list_uid = 0;
+static unsigned int ip_list_gid = 0;
module_param(ip_list_tot, uint, 0400);
+module_param(ip_pkt_list_tot, uint, 0400);
module_param(ip_list_hash_size, uint, 0400);
module_param(ip_list_perms, uint, 0400);
module_param(ip_list_uid, uint, S_IRUGO | S_IWUSR);
module_param(ip_list_gid, uint, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(ip_list_tot, "number of IPs to remember per list");
+MODULE_PARM_DESC(ip_pkt_list_tot, "number of packets per IP address to remember (max. 255)");
MODULE_PARM_DESC(ip_list_hash_size, "size of hash table used to look up IPs");
MODULE_PARM_DESC(ip_list_perms, "permissions on /proc/net/xt_recent/* files");
MODULE_PARM_DESC(ip_list_uid, "default owner of /proc/net/xt_recent/* files");
MODULE_PARM_DESC(ip_list_gid, "default owning group of /proc/net/xt_recent/* files");

-/* retained for backwards compatibility */
-static unsigned int ip_pkt_list_tot __read_mostly;
-module_param(ip_pkt_list_tot, uint, 0400);
-MODULE_PARM_DESC(ip_pkt_list_tot, "number of packets per IP address to remember (max. 255)");
-
-#define XT_RECENT_MAX_NSTAMPS 256
-
struct recent_entry {
struct list_head list;
struct list_head lru_list;
@@ -83,7 +79,6 @@ struct recent_table {
union nf_inet_addr mask;
unsigned int refcnt;
unsigned int entries;
- u8 nstamps_max_mask;
struct list_head lru_list;
struct list_head iphash[0];
};
@@ -95,8 +90,7 @@ struct recent_net {
#endif
};

-static int recent_net_id __read_mostly;
-
+static int recent_net_id;
static inline struct recent_net *recent_pernet(struct net *net)
{
return net_generic(net, recent_net_id);
@@ -177,15 +171,12 @@ recent_entry_init(struct recent_table *t
u_int16_t family, u_int8_t ttl)
{
struct recent_entry *e;
- unsigned int nstamps_max = t->nstamps_max_mask;

if (t->entries >= ip_list_tot) {
e = list_entry(t->lru_list.next, struct recent_entry, lru_list);
recent_entry_remove(t, e);
}
-
- nstamps_max += 1;
- e = kmalloc(sizeof(*e) + sizeof(e->stamps[0]) * nstamps_max,
+ e = kmalloc(sizeof(*e) + sizeof(e->stamps[0]) * ip_pkt_list_tot,
GFP_ATOMIC);
if (e == NULL)
return NULL;
@@ -206,7 +197,7 @@ recent_entry_init(struct recent_table *t

static void recent_entry_update(struct recent_table *t, struct recent_entry *e)
{
- e->index &= t->nstamps_max_mask;
+ e->index %= ip_pkt_list_tot;
e->stamps[e->index++] = jiffies;
if (e->index > e->nstamps)
e->nstamps = e->index;
@@ -335,7 +326,6 @@ static int recent_mt_check(const struct
kuid_t uid;
kgid_t gid;
#endif
- unsigned int nstamp_mask;
unsigned int i;
int ret = -EINVAL;
size_t sz;
@@ -359,33 +349,19 @@ static int recent_mt_check(const struct
return -EINVAL;
if ((info->check_set & XT_RECENT_REAP) && !info->seconds)
return -EINVAL;
- if (info->hit_count >= XT_RECENT_MAX_NSTAMPS) {
- pr_info("hitcount (%u) is larger than allowed maximum (%u)\n",
- info->hit_count, XT_RECENT_MAX_NSTAMPS - 1);
+ if (info->hit_count > ip_pkt_list_tot) {
+ pr_info("hitcount (%u) is larger than "
+ "packets to be remembered (%u)\n",
+ info->hit_count, ip_pkt_list_tot);
return -EINVAL;
}
if (info->name[0] == '\0' ||
strnlen(info->name, XT_RECENT_NAME_LEN) == XT_RECENT_NAME_LEN)
return -EINVAL;

- if (ip_pkt_list_tot && info->hit_count < ip_pkt_list_tot)
- nstamp_mask = roundup_pow_of_two(ip_pkt_list_tot) - 1;
- else if (info->hit_count)
- nstamp_mask = roundup_pow_of_two(info->hit_count) - 1;
- else
- nstamp_mask = 32 - 1;
-
mutex_lock(&recent_mutex);
t = recent_table_lookup(recent_net, info->name);
if (t != NULL) {
- if (info->hit_count > t->nstamps_max_mask) {
- pr_info("hitcount (%u) is larger than packets to be remembered (%u) for table %s\n",
- info->hit_count, t->nstamps_max_mask + 1,
- info->name);
- ret = -EINVAL;
- goto out;
- }
-
t->refcnt++;
ret = 0;
goto out;
@@ -401,7 +377,6 @@ static int recent_mt_check(const struct
goto out;
}
t->refcnt = 1;
- t->nstamps_max_mask = nstamp_mask;

memcpy(&t->mask, &info->mask, sizeof(t->mask));
strcpy(t->name, info->name);
@@ -522,12 +497,9 @@ static void recent_seq_stop(struct seq_f
static int recent_seq_show(struct seq_file *seq, void *v)
{
const struct recent_entry *e = v;
- struct recent_iter_state *st = seq->private;
- const struct recent_table *t = st->table;
unsigned int i;

- i = (e->index - 1) & t->nstamps_max_mask;
-
+ i = (e->index - 1) % ip_pkt_list_tot;
if (e->family == NFPROTO_IPV4)
seq_printf(seq, "src=%pI4 ttl: %u last_seen: %lu oldest_pkt: %u",
&e->addr.ip, e->ttl, e->stamps[i], e->index);
@@ -745,9 +717,7 @@ static int __init recent_mt_init(void)
{
int err;

- BUILD_BUG_ON_NOT_POWER_OF_2(XT_RECENT_MAX_NSTAMPS);
-
- if (!ip_list_tot || ip_pkt_list_tot >= XT_RECENT_MAX_NSTAMPS)
+ if (!ip_list_tot || !ip_pkt_list_tot || ip_pkt_list_tot > 255)
return -EINVAL;
ip_list_hash_size = 1 << fls(ip_list_tot);