vfio/iommu_type1: replace kvmalloc with kvzalloc and kfree with kvfree

virt inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I6FHYK
CVE: NA

--------------------------------

For security purposes, kvzalloc is used to allocate memory. Because
the memory may be allocated by vmalloc. So we replace kfree with
kvfree here.
Reported-by: NZhaolong Wang <wangzhaolong1@huawei.com>
Signed-off-by: NKunkun Jiang <jiangkunkun@huawei.com>
Reviewed-by: NKeqian Zhu <zhukeqian1@huawei.com>
Signed-off-by: NJialin Zhang <zhangjialin11@huawei.com>

drivers/vfio/vfio_iommu_type1.c

@@ -1129,7 +1129,7 @@ static int vfio_iova_dirty_log_clear(u64 __user *bitmap,
 	int ret = 0;
 
 	bitmap_size = DIRTY_BITMAP_BYTES(size >> pgshift);
-	bitmap_buffer = kvmalloc(bitmap_size, GFP_KERNEL);
+	bitmap_buffer = kvzalloc(bitmap_size, GFP_KERNEL);
 	if (!bitmap_buffer) {
 		ret = -ENOMEM;
 		goto out;
@@ -1179,7 +1179,7 @@ static int vfio_iova_dirty_log_clear(u64 __user *bitmap,
 	}
 
 out:
-	kfree(bitmap_buffer);
+	kvfree(bitmap_buffer);
 	return ret;
 }