diff --git a/drivers/virt/acrn/acrn_drv.h b/drivers/virt/acrn/acrn_drv.h
index 1be54ef..5663c17 100644
--- a/drivers/virt/acrn/acrn_drv.h
+++ b/drivers/virt/acrn/acrn_drv.h
@@ -48,6 +48,7 @@
  * @reserved:		Reserved.
  * @regions_num:	The number of vm_memory_region_op.
  * @regions_gpa:	Physical address of a vm_memory_region_op array.
+ * @regions_op:		Flexible array of vm_memory_region_op.
  *
  * HC_VM_SET_MEMORY_REGIONS uses this structure to manage EPT mappings of
  * multiple memory regions of a User VM. A &struct vm_memory_region_batch
@@ -55,10 +56,11 @@
  * ACRN Hypervisor.
  */
 struct vm_memory_region_batch {
-	u16	vmid;
-	u16	reserved[3];
-	u32	regions_num;
-	u64	regions_gpa;
+	u16			   vmid;
+	u16			   reserved[3];
+	u32			   regions_num;
+	u64			   regions_gpa;
+	struct vm_memory_region_op regions_op[];
 };
 
 /**
diff --git a/drivers/virt/acrn/mm.c b/drivers/virt/acrn/mm.c
index 3b1b1e7..b4ad8d4 100644
--- a/drivers/virt/acrn/mm.c
+++ b/drivers/virt/acrn/mm.c
@@ -192,7 +192,7 @@
 
 	/* Get the page number of the map region */
 	nr_pages = memmap->len >> PAGE_SHIFT;
-	pages = vzalloc(nr_pages * sizeof(struct page *));
+	pages = vzalloc(array_size(nr_pages, sizeof(*pages)));
 	if (!pages)
 		return -ENOMEM;
 
@@ -244,16 +244,15 @@
 	}
 
 	/* Prepare the vm_memory_region_batch */
-	regions_info = kzalloc(sizeof(*regions_info) +
-			       sizeof(*vm_region) * nr_regions,
-			       GFP_KERNEL);
+	regions_info = kzalloc(struct_size(regions_info, regions_op,
+					   nr_regions), GFP_KERNEL);
 	if (!regions_info) {
 		ret = -ENOMEM;
 		goto unmap_kernel_map;
 	}
 
 	/* Fill each vm_memory_region_op */
-	vm_region = (struct vm_memory_region_op *)(regions_info + 1);
+	vm_region = regions_info->regions_op;
 	regions_info->vmid = vm->vmid;
 	regions_info->regions_num = nr_regions;
 	regions_info->regions_gpa = virt_to_phys(vm_region);
diff --git a/fs/afs/security.c b/fs/afs/security.c
index 3c7a8fc..7c6a63a 100644
--- a/fs/afs/security.c
+++ b/fs/afs/security.c
@@ -219,8 +219,7 @@
 	 * yet.
 	 */
 	size++;
-	new = kzalloc(sizeof(struct afs_permits) +
-		      sizeof(struct afs_permit) * size, GFP_NOFS);
+	new = kzalloc(struct_size(new, permits, size), GFP_NOFS);
 	if (!new)
 		goto out_put;