Commit 780daa25 authored by Florian Westphal's avatar Florian Westphal Committed by Sasha Levin

netfilter: x_tables: validate e->target_offset early

[ Upstream commit bdf533de ]

We should check that e->target_offset is sane before
mark_source_chains gets called since it will fetch the target entry
for loop detection.
Signed-off-by: default avatarFlorian Westphal <fw@strlen.de>
Signed-off-by: default avatarPablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: default avatarSasha Levin <sasha.levin@oracle.com>
parent 1a1f239b
......@@ -469,14 +469,12 @@ static int mark_source_chains(const struct xt_table_info *newinfo,
return 1;
}
static inline int check_entry(const struct arpt_entry *e, const char *name)
static inline int check_entry(const struct arpt_entry *e)
{
const struct xt_entry_target *t;
if (!arp_checkentry(&e->arp)) {
duprintf("arp_tables: arp check failed %p %s.\n", e, name);
if (!arp_checkentry(&e->arp))
return -EINVAL;
}
if (e->target_offset + sizeof(struct xt_entry_target) > e->next_offset)
return -EINVAL;
......@@ -517,10 +515,6 @@ find_check_entry(struct arpt_entry *e, const char *name, unsigned int size)
struct xt_target *target;
int ret;
ret = check_entry(e, name);
if (ret)
return ret;
t = arpt_get_target(e);
target = xt_request_find_target(NFPROTO_ARP, t->u.user.name,
t->u.user.revision);
......@@ -565,6 +559,7 @@ static inline int check_entry_size_and_hooks(struct arpt_entry *e,
unsigned int valid_hooks)
{
unsigned int h;
int err;
if ((unsigned long)e % __alignof__(struct arpt_entry) != 0 ||
(unsigned char *)e + sizeof(struct arpt_entry) >= limit) {
......@@ -579,6 +574,10 @@ static inline int check_entry_size_and_hooks(struct arpt_entry *e,
return -EINVAL;
}
err = check_entry(e);
if (err)
return err;
/* Check hooks & underflows */
for (h = 0; h < NF_ARP_NUMHOOKS; h++) {
if (!(valid_hooks & (1 << h)))
......@@ -1239,7 +1238,7 @@ check_compat_entry_size_and_hooks(struct compat_arpt_entry *e,
}
/* For purposes of check_entry casting the compat entry is fine */
ret = check_entry((struct arpt_entry *)e, name);
ret = check_entry((struct arpt_entry *)e);
if (ret)
return ret;
......
......@@ -564,14 +564,12 @@ static void cleanup_match(struct xt_entry_match *m, struct net *net)
}
static int
check_entry(const struct ipt_entry *e, const char *name)
check_entry(const struct ipt_entry *e)
{
const struct xt_entry_target *t;
if (!ip_checkentry(&e->ip)) {
duprintf("ip check failed %p %s.\n", e, name);
if (!ip_checkentry(&e->ip))
return -EINVAL;
}
if (e->target_offset + sizeof(struct xt_entry_target) >
e->next_offset)
......@@ -661,10 +659,6 @@ find_check_entry(struct ipt_entry *e, struct net *net, const char *name,
struct xt_mtchk_param mtpar;
struct xt_entry_match *ematch;
ret = check_entry(e, name);
if (ret)
return ret;
j = 0;
mtpar.net = net;
mtpar.table = name;
......@@ -728,6 +722,7 @@ check_entry_size_and_hooks(struct ipt_entry *e,
unsigned int valid_hooks)
{
unsigned int h;
int err;
if ((unsigned long)e % __alignof__(struct ipt_entry) != 0 ||
(unsigned char *)e + sizeof(struct ipt_entry) >= limit) {
......@@ -742,6 +737,10 @@ check_entry_size_and_hooks(struct ipt_entry *e,
return -EINVAL;
}
err = check_entry(e);
if (err)
return err;
/* Check hooks & underflows */
for (h = 0; h < NF_INET_NUMHOOKS; h++) {
if (!(valid_hooks & (1 << h)))
......@@ -1505,7 +1504,7 @@ check_compat_entry_size_and_hooks(struct compat_ipt_entry *e,
}
/* For purposes of check_entry casting the compat entry is fine */
ret = check_entry((struct ipt_entry *)e, name);
ret = check_entry((struct ipt_entry *)e);
if (ret)
return ret;
......
......@@ -577,14 +577,12 @@ static void cleanup_match(struct xt_entry_match *m, struct net *net)
}
static int
check_entry(const struct ip6t_entry *e, const char *name)
check_entry(const struct ip6t_entry *e)
{
const struct xt_entry_target *t;
if (!ip6_checkentry(&e->ipv6)) {
duprintf("ip_tables: ip check failed %p %s.\n", e, name);
if (!ip6_checkentry(&e->ipv6))
return -EINVAL;
}
if (e->target_offset + sizeof(struct xt_entry_target) >
e->next_offset)
......@@ -675,10 +673,6 @@ find_check_entry(struct ip6t_entry *e, struct net *net, const char *name,
struct xt_mtchk_param mtpar;
struct xt_entry_match *ematch;
ret = check_entry(e, name);
if (ret)
return ret;
j = 0;
mtpar.net = net;
mtpar.table = name;
......@@ -742,6 +736,7 @@ check_entry_size_and_hooks(struct ip6t_entry *e,
unsigned int valid_hooks)
{
unsigned int h;
int err;
if ((unsigned long)e % __alignof__(struct ip6t_entry) != 0 ||
(unsigned char *)e + sizeof(struct ip6t_entry) >= limit) {
......@@ -756,6 +751,10 @@ check_entry_size_and_hooks(struct ip6t_entry *e,
return -EINVAL;
}
err = check_entry(e);
if (err)
return err;
/* Check hooks & underflows */
for (h = 0; h < NF_INET_NUMHOOKS; h++) {
if (!(valid_hooks & (1 << h)))
......@@ -1520,7 +1519,7 @@ check_compat_entry_size_and_hooks(struct compat_ip6t_entry *e,
}
/* For purposes of check_entry casting the compat entry is fine */
ret = check_entry((struct ip6t_entry *)e, name);
ret = check_entry((struct ip6t_entry *)e);
if (ret)
return ret;
......
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