[PATCH stable-4.1 v2] netfilter: x_tables: fix stable backport

[Michal Kubecek]

Stable-4.1 backport of mainline commit 364723410175 ("netfilter:
x_tables: validate targets of jumps") doesn't handle correctly the fact
that 4.1 kernel is missing commit 482cfc318559 ("netfilter: xtables:
avoid percpu ruleset duplication") so that t->entries is still a per-cpu
array in find_jump_target().

Use the same fix as e.g. stable-3.14 backport.

Fixes: 8163327a3a92 ("netfilter: x_tables: validate targets of jumps")
Signed-off-by: Michal Kubecek <mkube...@suse.cz>
---
 net/ipv4/netfilter/arp_tables.c | 5 +++--
 net/ipv4/netfilter/ip_tables.c  | 5 +++--
 net/ipv6/netfilter/ip6_tables.c | 5 +++--
 3 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/net/ipv4/netfilter/arp_tables.c b/net/ipv4/netfilter/arp_tables.c
index 2953ee9e5fa0..49e145640ee7 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 */
diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c
index 3bcf28bf1525..52a883645899 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 */
diff --git a/net/ipv6/netfilter/ip6_tables.c b/net/ipv6/netfilter/ip6_tables.c
index 5254d76dfce8..b77bf6dab70c 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 */
-- 
2.9.2