[PATCH] slub: fix possible NULL pointer dereference

[Cyrill Gorcunov <gorcunov@gmail.com>]

This patch fix possible NULL pointer dereference if kzalloc
failed. To be able to return proper error code the function
return type is changed to ssize_t (according to callees and
sysfs definitions).

Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
---

Index: linux-2.6.git/mm/slub.c
===================================================================
--- linux-2.6.git.orig/mm/slub.c	2008-03-02 22:53:27.000000000 +0300
+++ linux-2.6.git/mm/slub.c	2008-03-02 23:02:27.000000000 +0300
@@ -3591,8 +3591,8 @@ enum slab_stat_type {
 #define SO_CPU		(1 << SL_CPU)
 #define SO_OBJECTS	(1 << SL_OBJECTS)
 
-static unsigned long slab_objects(struct kmem_cache *s,
-			char *buf, unsigned long flags)
+static ssize_t slab_objects(struct kmem_cache *s,
+			    char *buf, unsigned long flags)
 {
 	unsigned long total = 0;
 	int cpu;
@@ -3602,6 +3602,8 @@ static unsigned long slab_objects(struct
 	unsigned long *per_cpu;
 
 	nodes = kzalloc(2 * sizeof(unsigned long) * nr_node_ids, GFP_KERNEL);
+	if (!nodes)
+		return -ENOMEM;
 	per_cpu = nodes + nr_node_ids;
 
 	for_each_possible_cpu(cpu) {