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Message-ID: <lsq.1461711741.589720695@decadent.org.uk>
Date: Wed, 27 Apr 2016 01:02:21 +0200
From: Ben Hutchings <ben@...adent.org.uk>
To: linux-kernel@...r.kernel.org, stable@...r.kernel.org
CC: akpm@...ux-foundation.org, "Florian Westphal" <fw@...len.de>,
"Pablo Neira Ayuso" <pablo@...filter.org>
Subject: [PATCH 3.16 179/217] netfilter: x_tables: validate
e->target_offset early
3.16.35-rc1 review patch. If anyone has any objections, please let me know.
------------------
From: Florian Westphal <fw@...len.de>
commit bdf533de6968e9686df777dc178486f600c6e617 upstream.
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: Florian Westphal <fw@...len.de>
Signed-off-by: Pablo Neira Ayuso <pablo@...filter.org>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@...adent.org.uk>
---
net/ipv4/netfilter/arp_tables.c | 17 ++++++++---------
net/ipv4/netfilter/ip_tables.c | 17 ++++++++---------
net/ipv6/netfilter/ip6_tables.c | 17 ++++++++---------
3 files changed, 24 insertions(+), 27 deletions(-)
--- a/net/ipv4/netfilter/arp_tables.c
+++ b/net/ipv4/netfilter/arp_tables.c
@@ -470,14 +470,12 @@ static int mark_source_chains(const stru
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;
@@ -518,10 +516,6 @@ find_check_entry(struct arpt_entry *e, c
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);
@@ -566,6 +560,7 @@ static inline int check_entry_size_and_h
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) {
@@ -580,6 +575,10 @@ static inline int check_entry_size_and_h
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)))
@@ -1237,7 +1236,7 @@ check_compat_entry_size_and_hooks(struct
}
/* 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;
--- a/net/ipv4/netfilter/ip_tables.c
+++ b/net/ipv4/netfilter/ip_tables.c
@@ -565,14 +565,12 @@ static void cleanup_match(struct xt_entr
}
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)
@@ -662,10 +660,6 @@ find_check_entry(struct ipt_entry *e, st
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;
@@ -729,6 +723,7 @@ check_entry_size_and_hooks(struct ipt_en
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) {
@@ -743,6 +738,10 @@ check_entry_size_and_hooks(struct ipt_en
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)))
@@ -1503,7 +1502,7 @@ check_compat_entry_size_and_hooks(struct
}
/* 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;
--- a/net/ipv6/netfilter/ip6_tables.c
+++ b/net/ipv6/netfilter/ip6_tables.c
@@ -575,14 +575,12 @@ static void cleanup_match(struct xt_entr
}
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)
@@ -673,10 +671,6 @@ find_check_entry(struct ip6t_entry *e, s
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;
@@ -740,6 +734,7 @@ check_entry_size_and_hooks(struct ip6t_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) {
@@ -754,6 +749,10 @@ check_entry_size_and_hooks(struct ip6t_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)))
@@ -1515,7 +1514,7 @@ check_compat_entry_size_and_hooks(struct
}
/* 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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