[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 <mort@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

2 files changed, 4 insertions, 0 deletions

diff --git a/include/linux/capability.h b/include/linux/capability.h
index 8d139f4acf23..6b4618902d3d 100644
--- a/include/linux/capability.h
+++ b/include/linux/capability.h
@@ -233,6 +233,7 @@ typedef __u32 kernel_cap_t;
 /* 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
 
diff --git a/mm/vmscan.c b/mm/vmscan.c
index cfffe5098d53..ab631a3c62c3 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1375,6 +1375,9 @@ asmlinkage long sys_set_zone_reclaim(unsigned int node, unsigned int zone,
         struct zone *z;
         int i;
 
+        if (!capable(CAP_SYS_ADMIN))
+                return -EACCES;
+
         if (node >= MAX_NUMNODES || !node_online(node))
                 return -EINVAL;