Hello.

On 03/04/2014 10:34 AM, Chuansheng Liu wrote:

When the request length is aligned to maxpacketsize, sometimes
the return length ret > the user space requested len.

At that time, we will use min_t(size_t, ret, len) to limit the
size in case of user data buffer overflow.

But we need return the min_t(size_t, ret, len) to tell the user
space rightly also.

Acked-by: Michal Nazarewicz <min...@mina86.com>
Reviewed-by: David Cohen <david.a.co...@linux.intel.com>
Signed-off-by: Chuansheng Liu <chuansheng....@intel.com>
---
  drivers/usb/gadget/f_fs.c | 14 ++++++++------
  1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/drivers/usb/gadget/f_fs.c b/drivers/usb/gadget/f_fs.c
index 42f7a0e..780f877 100644
--- a/drivers/usb/gadget/f_fs.c
+++ b/drivers/usb/gadget/f_fs.c
@@ -845,12 +845,14 @@ static ssize_t ffs_epfile_io(struct file *file, struct 
ffs_io_data *io_data)
                         * we may end up with more data then user space has
                         * space for.
                         */
-                       ret = ep->status;
-                       if (io_data->read && ret > 0 &&
-                           unlikely(copy_to_user(io_data->buf, data,
-                                                 min_t(size_t, ret,
-                                                 io_data->len))))
-                               ret = -EFAULT;
+                               ret = ep->status;

   Why the indentation jumped suddenly to the right?

+                               if (io_data->read && ret > 0) {
+                                       ret = min_t(size_t, ret, io_data->len);
+
+                                       if (unlikely(copy_to_user(io_data->buf,
+                                               data, ret)))
+                                               ret = -EFAULT;
+                               }
                        }
                        kfree(data);

WBR, Sergei

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