[Patch] slub: Fix a missing-check bug in mm/slub.c file of Linux 5.1.1

From: Gen Zhang
Date: Wed May 15 2019 - 02:46:57 EST

Pointer s is allocated with kmem_cache_zalloc(). And s is used in the
follwoing codes. However, when kmem_cache_zalloc fails, using s will
cause null pointer dereference and the kernel will go wrong. Thus we
check whether the kmem_cache_zalloc fails.

Signed-off-by: Gen Zhang <blackgod016574@xxxxxxxxx>

--- mm/slub.c
+++ mm/slub.c
@@ -4201,6 +4201,8 @@ static struct kmem_cache * __init bootst
int node;
struct kmem_cache *s = kmem_cache_zalloc(kmem_cache, GFP_NOWAIT);
+ if (!s)
+ return ERR_PTR(-ENOMEM);
struct kmem_cache_node *n;

memcpy(s, static_cache, kmem_cache->object_size);