cxl/mem: Return -EFAULT if copy_to_user() fails

The copy_to_user() function returns the number of bytes remaining to be
copied, but we want to return -EFAULT if the copy doesn't complete.

Fixes: b754ffbbc0ee ("cxl/mem: Add basic IOCTL interface")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/YC+K3kgzqm20zCWY@mwanda
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

diff --git a/drivers/cxl/mem.c b/drivers/cxl/mem.c
index 6d7d387..df895bc 100644 (file)
--- a/drivers/cxl/mem.c
+++ b/drivers/cxl/mem.c
@@ -752,7 +752,10 @@ static int cxl_send_cmd(struct cxl_memdev *cxlmd,
        if (rc)
                return rc;
 
-       return copy_to_user(s, &send, sizeof(send));
+       if (copy_to_user(s, &send, sizeof(send)))
+               return -EFAULT;
+
+       return 0;
 }
 
 static long __cxl_memdev_ioctl(struct cxl_memdev *cxlmd, unsigned int cmd,