[PATCH] VM: add capabilites check to set_zone_reclaim

Add a capability check to sys_set_zone_reclaim(). This syscall is not
something that should be available to a user.

Signed-off-by: Martin Hicks <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

include/linux/capability.h

···
 /* Allow enabling/disabling tagged queuing on SCSI controllers and sending
    arbitrary SCSI commands */
 /* Allow setting encryption key on loopback filesystem */
+/* Allow setting zone reclaim policy */
 
 #define CAP_SYS_ADMIN        21
 

mm/vmscan.c

···
 	struct zone *z;
 	int i;
 
+	if (!capable(CAP_SYS_ADMIN))
+		return -EACCES;
+
 	if (node >= MAX_NUMNODES || !node_online(node))
 		return -EINVAL;