Hi!
On Fri, 2021-03-26 at 23:02 +0200, Alaa Emad wrote:
> Reported-by: syzbot+a4e309017a5f3a24c7b3@xxxxxxxxxxxxxxxxxxxxxxxxx
> Signed-off-by: Alaa Emad <alaaemadhossney.ae@xxxxxxxxx>
>
> ---
> Changes in v2:
> - Fix the error occured because of pervious fix.
> ---
> drivers/media/usb/gspca/sq905.c | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/media/usb/gspca/sq905.c
> b/drivers/media/usb/gspca/sq905.c
> index 97799cfb832e..57206dd2e1a0 100644
> --- a/drivers/media/usb/gspca/sq905.c
> +++ b/drivers/media/usb/gspca/sq905.c
> @@ -157,8 +157,8 @@ static int sq905_ack_frame(struct gspca_dev
> *gspca_dev)
> static int
> sq905_read_data(struct gspca_dev *gspca_dev, u8 *data, int size, int
> need_lock)
> {
> - int ret;
> - int act_len;
> + int ret;
> + int act_len;
>
> gspca_dev->usb_buf[0] = '\0';
> if (need_lock)
> @@ -180,8 +180,8 @@ sq905_read_data(struct gspca_dev *gspca_dev, u8
> *data, int size, int need_lock)
> data, size, &act_len, SQ905_DATA_TIMEOUT);
>
> /* successful, it returns 0, otherwise negative */
> - if (ret < 0 || act_len != size) {
> - pr_err("bulk read fail (%d) len %d/%d\n", ret, act_len,
> size);
> + if (ret < 0 || act_len != size) {
> + pr_err("bulk read fail (%d) len %d/%d\n", ret, ret < 0 ?
> -1 : act_len, size);
> return -EIO;
> }
> return 0;
> --
> 2.25.1
>
I skimmed through code, and I'm not sure about Dmitry's approach,
because I think usb_submit_urb() can return some valid urb-
>actual_length and error code:
if (!wait_for_completion_timeout(&ctx.done, expire)) {
usb_kill_urb(urb);
retval = (ctx.status == -ENOENT ? -ETIMEDOUT :
ctx.status);
dev_dbg(&urb->dev->dev,
"%s timed out on ep%d%s len=%u/%u\n",
current->comm,
usb_endpoint_num(&urb->ep->desc),
usb_urb_dir_in(urb) ? "in" : "out",
urb->actual_length,
urb->transfer_buffer_length);
} else
retval = ctx.status;
...
if (actual_length)
*actual_length = urb->actual_length;
I believe, that this info might be useful.
Im not sure about it, i didn't found any examples of this log and have
no idea how to reproduce it, it's just my thoughts. Maybe, one of the
maintainers will correct me
--
With regards,
Pavel Skripkin
