diff --git a/net/ipv4/netfilter/arp_tables.c b/net/ipv4/netfilter/arp_tables.c index 95c9b6eece25..92305a1a021a 100644 --- a/net/ipv4/netfilter/arp_tables.c +++ b/net/ipv4/netfilter/arp_tables.c @@ -254,9 +254,10 @@ unsigned int arpt_do_table(struct sk_buff *skb, static const char nulldevname[IFNAMSIZ] __attribute__((aligned(sizeof(long)))); unsigned int verdict = NF_DROP; const struct arphdr *arp; - struct arpt_entry *e, *back; + struct arpt_entry *e, **jumpstack; const char *indev, *outdev; const void *table_base; + unsigned int cpu, stackidx = 0; const struct xt_table_info *private; struct xt_action_param acpar; unsigned int addend; @@ -270,15 +271,16 @@ unsigned int arpt_do_table(struct sk_buff *skb, local_bh_disable(); 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; + jumpstack = (struct arpt_entry **)private->jumpstack[cpu]; e = get_entry(table_base, private->hook_entry[hook]); - back = get_entry(table_base, private->underflow[hook]); acpar.in = state->in; acpar.out = state->out; @@ -312,18 +314,23 @@ unsigned int arpt_do_table(struct sk_buff *skb, verdict = (unsigned int)(-v) - 1; break; } - e = back; - back = get_entry(table_base, back->comefrom); + if (stackidx == 0) { + e = get_entry(table_base, + private->underflow[hook]); + } else { + e = jumpstack[--stackidx]; + e = arpt_next_entry(e); + } continue; } if (table_base + v != arpt_next_entry(e)) { - /* Save old back ptr in next entry */ - struct arpt_entry *next = arpt_next_entry(e); - next->comefrom = (void *)back - table_base; - /* set back pointer to next entry */ - back = next; + if (stackidx >= private->stacksize) { + verdict = NF_DROP; + break; + } + jumpstack[stackidx++] = e; } e = get_entry(table_base, v);