Re: [PATCH net-next] octeontx2-af: Allocate ikpu2 with ARRAY_SIZE()

From: Kees Cook <kees+treewide@kernel.org>

In preparation for making the devm_kmalloc family of allocators type
aware, we need to make sure that the returned type from the allocation
matches the type of the variable being assigned. (Before, the allocator
would always return "void *", which can be implicitly cast to any
pointer type.)

This is allocating room for a copy of ikpu_action_entries, which is an
array of struct npc_kpu_profile_action, but it asked for a single object
the size of the whole array, which would make the allocation type a
pointer to the array rather than the "struct npc_kpu_profile_action *"
being assigned. Allocate ARRAY_SIZE-many entries instead. The resulting
allocation size is the same.

--- a/drivers/net/ethernet/marvell/octeontx2/af/rvu_npc.c
+++ b/drivers/net/ethernet/marvell/octeontx2/af/rvu_npc.c

@@ -1959,8 +1959,9 @@ static int npc_apply_custom_kpu_from_fs(struct rvu *rvu,
 	fw = rvu->kpu_fwdata;

 	/* Binary blob contains ikpu actions entries at start of data[0] */
-	profile->ikpu2 = devm_kcalloc(rvu->dev, 1,
-				      sizeof(ikpu_action_entries),
+	profile->ikpu2 = devm_kcalloc(rvu->dev,
+				      ARRAY_SIZE(ikpu_action_entries),
+				      sizeof(*profile->ikpu2),
 				      GFP_KERNEL);