From: "Du, Changbin" <changbin.du@intel.com>
To: Felipe Balbi <felipe.balbi@linux.intel.com>,
Al Viro <viro@zeniv.linux.org.uk>
Cc: "gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>,
"mina86@mina86.com" <mina86@mina86.com>,
"rui.silva@linaro.org" <rui.silva@linaro.org>,
"k.opasiak@samsung.com" <k.opasiak@samsung.com>,
"lars@metafoo.de" <lars@metafoo.de>,
"linux-usb@vger.kernel.org" <linux-usb@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: RE: [PATCH] usb: gadget: f_fs: report error if excess data received
Date: Thu, 12 May 2016 09:51:49 +0000 [thread overview]
Message-ID: <0C18FE92A7765D4EB9EE5D38D86A563A05D2F2E4@SHSMSX103.ccr.corp.intel.com> (raw)
In-Reply-To: <87wpmzeikv.fsf@linux.intel.com>
Hi,
>
> we need a min() here. Better version below:
No need. copy_to_iter will do it for us.
Best Regards,
Du, Changbin
>
> diff --git a/drivers/usb/gadget/function/f_fs.c
> b/drivers/usb/gadget/function/f_fs.c
> index 73515d54e1cc..6c49b152f46e 100644
> --- a/drivers/usb/gadget/function/f_fs.c
> +++ b/drivers/usb/gadget/function/f_fs.c
> @@ -156,6 +156,8 @@ struct ffs_io_data {
> struct usb_request *req;
>
> struct ffs_data *ffs;
> +
> + ssize_t expected_len;
> };
>
> struct ffs_desc_helper {
> @@ -730,8 +732,10 @@ static ssize_t ffs_epfile_io(struct file *file, struct
> ffs_io_data *io_data)
> * Controller may require buffer size to be aligned to
> * maxpacketsize of an out endpoint.
> */
> - if (io_data->read)
> + if (io_data->read) {
> + io_data->expected_len = data_len;
> data_len = usb_ep_align_maybe(gadget, ep->ep,
> data_len);
> + }
> spin_unlock_irq(&epfile->ffs->eps_lock);
>
> data = kmalloc(data_len, GFP_KERNEL);
> @@ -811,7 +815,15 @@ static ssize_t ffs_epfile_io(struct file *file, struct
> ffs_io_data *io_data)
> */
> ret = interrupted ? -EINTR : ep->status;
> if (io_data->read && ret > 0) {
> - ret = copy_to_iter(data, ret, &io_data->data);
> + ssize_t bytes;
> +
> + if (ret > io_data->expected_len)
> + pr_debug("FFS: size mismatch: %zd for %zd",
> + ret, io_data->expected_len);
> +
> + bytes = min(ret, io_data->expected_len);
> +
> + ret = copy_to_iter(data, bytes, &io_data->data);
> if (!ret)
> ret = -EFAULT;
> }
>
>
> --
> balbi
next prev parent reply other threads:[~2016-05-12 9:51 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-05-11 10:19 [PATCH] usb: gadget: f_fs: report error if excess data received changbin.du
2016-05-11 10:59 ` Felipe Balbi
2016-05-11 12:30 ` Michal Nazarewicz
2016-05-12 4:25 ` Du, Changbin
2016-05-12 4:21 ` Du, Changbin
2016-05-12 6:52 ` Felipe Balbi
2016-05-12 7:30 ` Du, Changbin
2016-05-12 7:46 ` Felipe Balbi
2016-05-12 8:16 ` Du, Changbin
2016-05-12 9:15 ` Felipe Balbi
2016-05-12 9:22 ` Felipe Balbi
2016-05-12 9:51 ` Du, Changbin [this message]
2016-05-12 9:39 ` Du, Changbin
2016-05-12 10:13 ` Felipe Balbi
2016-05-12 10:14 ` Felipe Balbi
2016-05-12 10:45 ` Du, Changbin
2016-05-12 11:22 ` Felipe Balbi
2016-05-13 5:52 ` Du, Changbin
2016-05-13 6:36 ` Felipe Balbi
2016-05-13 10:32 ` Du, Changbin
2016-05-13 14:29 ` Alan Stern
2016-05-14 20:39 ` Michal Nazarewicz
2016-05-16 12:57 ` Felipe Balbi
2016-05-16 13:08 ` Michal Nazarewicz
2016-05-16 13:16 ` Felipe Balbi
2016-05-16 19:09 ` Michal Nazarewicz
2016-05-17 2:53 ` Du, Changbin
2016-05-18 9:45 ` Michal Nazarewicz
2016-05-18 10:15 ` Felipe Balbi
2016-05-18 13:39 ` Michal Nazarewicz
2016-05-19 2:54 ` Du, Changbin
2016-05-19 7:34 ` Michal Nazarewicz
2016-05-19 8:49 ` Du, Changbin
2016-05-19 2:31 ` Du, Changbin
2016-05-16 16:05 ` Michal Nazarewicz
2016-05-16 16:27 ` Lars-Peter Clausen
2016-05-16 16:48 ` Michal Nazarewicz
2016-05-16 16:35 ` Krzysztof Opasiak
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