[NETFILTER]: ip_tables: fix table locking in ipt_do_table

table->private might change because of ruleset changes, don't use it without
holding the lock.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 1 deletions

diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c
index f316ff5fd8a6..048514f15f2f 100644
--- a/net/ipv4/netfilter/ip_tables.c
+++ b/net/ipv4/netfilter/ip_tables.c
@@ -230,7 +230,7 @@ ipt_do_table(struct sk_buff **pskb,
         const char *indev, *outdev;
         void *table_base;
         struct ipt_entry *e, *back;
-        struct xt_table_info *private = table->private;
+        struct xt_table_info *private;
 
         /* Initialization */
         ip = (*pskb)->nh.iph;
@@ -247,6 +247,7 @@ ipt_do_table(struct sk_buff **pskb,
 
         read_lock_bh(&table->lock);
         IP_NF_ASSERT(table->valid_hooks & (1 << hook));
+        private = table->private;
         table_base = (void *)private->entries[smp_processor_id()];
         e = get_entry(table_base, private->hook_entry[hook]);