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 <mina86@xxxxxxxxxx> Reviewed-by: David Cohen <david.a.cohen@xxxxxxxxxxxxxxx> Signed-off-by: Chuansheng Liu <chuansheng.liu@xxxxxxxxx> --- 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);
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