diff --git a/drivers/staging/lustre/lustre/llite/file.c b/drivers/staging/lustre/lustre/llite/file.c
index 562e33751197..d87f96d9e0fa 100644
--- a/drivers/staging/lustre/lustre/llite/file.c
+++ b/drivers/staging/lustre/lustre/llite/file.c
@@ -1829,6 +1829,10 @@ static int ll_ioctl_fiemap(struct inode *inode, unsigned long arg)
 	if (get_user(extent_count,
 	    &((struct ll_user_fiemap __user *)arg)->fm_extent_count))
 		return -EFAULT;
+
+	if (extent_count >=
+	    (SIZE_MAX - sizeof(*fiemap_s)) / sizeof(struct ll_fiemap_extent))
+		return -EINVAL;
 	num_bytes = sizeof(*fiemap_s) + (extent_count *
 					 sizeof(struct ll_fiemap_extent));