net:rfs: adjust table size checking

Make sure root user does not try something stupid. Also make sure mask field in struct rps_sock_flow_table does not share a cache line with the potentially often dirtied flow table. Signed-off-by: Eric Dumazet <edumazet@google.com> Fixes: 567e4b7 ("net: rfs: add hash collision detection") Signed-off-by: David S. Miller <davem@davemloft.net>
aarch64-laptops · Feb 9, 2015 · 93c1af6 · 93c1af6
1 parent acde2c2
commit 93c1af6
Show file tree

Hide file tree

Showing 2 changed files with 3 additions and 2 deletions.
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
@@ -653,7 +653,8 @@ struct rps_dev_flow_table {
  */
 struct rps_sock_flow_table {
 	u32	mask;
-	u32	ents[0];
+
+	u32	ents[0] ____cacheline_aligned_in_smp;
 };
 #define	RPS_SOCK_FLOW_TABLE_SIZE(_num) (offsetof(struct rps_sock_flow_table, ents[_num]))
 

diff --git a/net/core/sysctl_net_core.c b/net/core/sysctl_net_core.c
@@ -52,7 +52,7 @@ static int rps_sock_flow_sysctl(struct ctl_table *table, int write,
 
 	if (write) {
 		if (size) {
-			if (size > 1<<30) {
+			if (size > 1<<29) {
 				/* Enforce limit to prevent overflow */
 				mutex_unlock(&sock_flow_mutex);
 				return -EINVAL;