netfilter: x_tables: fix ordering of jumpstack allocation and table update

[~andy/linux] / net / ipv4 / netfilter / ip_tables.c

diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c
index d23118d95ff9291401396953d094391db0e2e44e..718dfbd30cbe09560c1d545525b446fb5695f6af 100644 (file)
--- a/net/ipv4/netfilter/ip_tables.c
+++ b/net/ipv4/netfilter/ip_tables.c
@@ -327,6 +327,11 @@ ipt_do_table(struct sk_buff *skb,
        addend = xt_write_recseq_begin();
        private = table->private;
        cpu        = smp_processor_id();
+       /*
+        * Ensure we load private-> members after we've fetched the base
+        * pointer.
+        */
+       smp_read_barrier_depends();
        table_base = private->entries[cpu];
        jumpstack  = (struct ipt_entry **)private->jumpstack[cpu];
        stackptr   = per_cpu_ptr(private->stackptr, cpu);