Stable-4.1 backport of Florian Westphal's CVE-2016-4997 fixes doesn't
handle correctly the fact that 4.1 kernel is missing commit
482cfc318559 ("netfilter: xtables: avoid percpu ruleset duplication").
Add code fragments needed for pre-4.2 kernels.
Fixes: 8163327a3a92 ("netfilter: x_tables: validate targets of jumps")
Fixes: af815d264b7e ("netfilter: x_tables: do compat validation via translate_table")
Signed-off-by: Michal Kubecek <mkubecek@xxxxxxx>
---
net/ipv4/netfilter/arp_tables.c | 10 ++++++++--
net/ipv4/netfilter/ip_tables.c | 13 +++++++++----
net/ipv6/netfilter/ip6_tables.c | 14 ++++++++++----
3 files changed, 27 insertions(+), 10 deletions(-)
diff --git a/net/ipv4/netfilter/arp_tables.c b/net/ipv4/netfilter/arp_tables.c
index 2953ee9e5fa0..015611cc937c 100644
--- a/net/ipv4/netfilter/arp_tables.c
+++ b/net/ipv4/netfilter/arp_tables.c
@@ -363,11 +363,12 @@ static inline bool unconditional(const struct arpt_entry *e)
}
static bool find_jump_target(const struct xt_table_info *t,
+ const void *entry0,
const struct arpt_entry *target)
{
struct arpt_entry *iter;
- xt_entry_foreach(iter, t->entries, t->size) {
+ xt_entry_foreach(iter, entry0, t->size) {
if (iter == target)
return true;
}
@@ -469,7 +470,7 @@ static int mark_source_chains(const struct xt_table_info *newinfo,
pos, newpos);
e = (struct arpt_entry *)
(entry0 + newpos);
- if (!find_jump_target(newinfo, e))
+ if (!find_jump_target(newinfo, entry0, e))
return 0;
} else {
/* ... this is a fallthru */
@@ -1358,6 +1359,11 @@ static int translate_compat_table(struct xt_table_info **pinfo,
if (ret)
goto free_newinfo;
+ /* And one copy for every other CPU */
+ for_each_possible_cpu(i)
+ if (newinfo->entries[i] && newinfo->entries[i] != entry1)
+ memcpy(newinfo->entries[i], entry1, newinfo->size);
+
*pinfo = newinfo;
*pentry0 = entry1;
xt_free_table_info(info);
diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c
index 3bcf28bf1525..3a748d796ec1 100644
--- a/net/ipv4/netfilter/ip_tables.c
+++ b/net/ipv4/netfilter/ip_tables.c
@@ -439,11 +439,12 @@ ipt_do_table(struct sk_buff *skb,
}
static bool find_jump_target(const struct xt_table_info *t,
+ const void *entry0,
const struct ipt_entry *target)
{
struct ipt_entry *iter;
- xt_entry_foreach(iter, t->entries, t->size) {
+ xt_entry_foreach(iter, entry0, t->size) {
if (iter == target)
return true;
}
@@ -549,7 +550,7 @@ mark_source_chains(const struct xt_table_info *newinfo,
pos, newpos);
e = (struct ipt_entry *)
(entry0 + newpos);
- if (!find_jump_target(newinfo, e))
+ if (!find_jump_target(newinfo, entry0, e))
return 0;
} else {
/* ... this is a fallthru */
@@ -1479,8 +1480,7 @@ check_compat_entry_size_and_hooks(struct compat_ipt_entry *e,
entry_offset = (void *)e - (void *)base;
j = 0;
xt_ematch_foreach(ematch, e) {
- ret = compat_find_calc_match(ematch, &e->ip, e->comefrom,
- &off);
+ ret = compat_find_calc_match(ematch, &e->ip, e->comefrom, &off);
if (ret != 0)
goto release_matches;
++j;
@@ -1635,6 +1635,11 @@ translate_compat_table(struct net *net,
if (ret)
goto free_newinfo;
+ /* And one copy for every other CPU */
+ for_each_possible_cpu(i)
+ if (newinfo->entries[i] && newinfo->entries[i] != entry1)
+ memcpy(newinfo->entries[i], entry1, newinfo->size);
+
*pinfo = newinfo;
*pentry0 = entry1;
xt_free_table_info(info);
diff --git a/net/ipv6/netfilter/ip6_tables.c b/net/ipv6/netfilter/ip6_tables.c
index 5254d76dfce8..1ac4bcdefc53 100644
--- a/net/ipv6/netfilter/ip6_tables.c
+++ b/net/ipv6/netfilter/ip6_tables.c
@@ -452,11 +452,12 @@ ip6t_do_table(struct sk_buff *skb,
}
static bool find_jump_target(const struct xt_table_info *t,
+ const void *entry0,
const struct ip6t_entry *target)
{
struct ip6t_entry *iter;
- xt_entry_foreach(iter, t->entries, t->size) {
+ xt_entry_foreach(iter, entry0, t->size) {
if (iter == target)
return true;
}
@@ -562,7 +563,7 @@ mark_source_chains(const struct xt_table_info *newinfo,
pos, newpos);
e = (struct ip6t_entry *)
(entry0 + newpos);
- if (!find_jump_target(newinfo, e))
+ if (!find_jump_target(newinfo, entry0, e))
return 0;
} else {
/* ... this is a fallthru */
@@ -1493,8 +1494,8 @@ check_compat_entry_size_and_hooks(struct compat_ip6t_entry *e,
entry_offset = (void *)e - (void *)base;
j = 0;
xt_ematch_foreach(ematch, e) {
- ret = compat_find_calc_match(ematch, &e->ipv6, e->comefrom,
- &off);
+ ret = compat_find_calc_match(ematch,
+ &e->ipv6, e->comefrom, &off);
if (ret != 0)
goto release_matches;
++j;
@@ -1640,6 +1641,11 @@ translate_compat_table(struct net *net,
if (ret)
goto free_newinfo;
+ /* And one copy for every other CPU */
+ for_each_possible_cpu(i)
+ if (newinfo->entries[i] && newinfo->entries[i] != entry1)
+ memcpy(newinfo->entries[i], entry1, newinfo->size);
+
*pinfo = newinfo;
*pentry0 = entry1;
xt_free_table_info(info);
--
2.9.2
--
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