[NETFILTER]: Fix OOPSes on machines with discontiguous cpu numbering.

Original patch by Harald Welte, with feedback from Herbert Xu
and testing by Sébastien Bernard.

EBTABLES, ARP tables, and IP/IP6 tables all assume that cpus
are numbered linearly.  That is not necessarily true.

This patch fixes that up by calculating the largest possible
cpu number, and allocating enough per-cpu structure space given
that.

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 9 insertions, 5 deletions

diff --git a/net/ipv4/netfilter/arp_tables.c b/net/ipv4/netfilter/arp_tables.c
index fa163425668..a7969286e6e 100644
--- a/net/ipv4/netfilter/arp_tables.c
+++ b/net/ipv4/netfilter/arp_tables.c
@@ -716,8 +716,10 @@ static int translate_table(const char *name,
 	}
 
 	/* And one copy for every other CPU */
-	for (i = 1; i < num_possible_cpus(); i++) {
-		memcpy(newinfo->entries + SMP_ALIGN(newinfo->size)*i,
+	for_each_cpu(i) {
+		if (i == 0)
+			continue;
+		memcpy(newinfo->entries + SMP_ALIGN(newinfo->size) * i,
 		       newinfo->entries,
 		       SMP_ALIGN(newinfo->size));
 	}
@@ -767,7 +769,7 @@ static void get_counters(const struct arpt_table_info *t,
 	unsigned int cpu;
 	unsigned int i;
 
-	for (cpu = 0; cpu < num_possible_cpus(); cpu++) {
+	for_each_cpu(cpu) {
 		i = 0;
 		ARPT_ENTRY_ITERATE(t->entries + TABLE_OFFSET(t, cpu),
 				   t->size,
@@ -885,7 +887,8 @@ static int do_replace(void __user *user, unsigned int len)
 		return -ENOMEM;
 
 	newinfo = vmalloc(sizeof(struct arpt_table_info)
-			  + SMP_ALIGN(tmp.size) * num_possible_cpus());
+			  + SMP_ALIGN(tmp.size) *
+			  		(highest_possible_processor_id()+1));
 	if (!newinfo)
 		return -ENOMEM;
 
@@ -1158,7 +1161,8 @@ int arpt_register_table(struct arpt_table *table,
 		= { 0, 0, 0, { 0 }, { 0 }, { } };
 
 	newinfo = vmalloc(sizeof(struct arpt_table_info)
-			  + SMP_ALIGN(repl->size) * num_possible_cpus());
+			  + SMP_ALIGN(repl->size) *
+			  		(highest_possible_processor_id()+1));
 	if (!newinfo) {
 		ret = -ENOMEM;
 		return ret;