On Tue, 22 Oct 2019, Suwan Kim wrote:
> iso_buffer should be set to NULL after use and free in the while loop.
> In the case of isochronous URB in the while loop, iso_buffer is
> allocated and after sending it to server, buffer is deallocated. And
> then, if the next URB in the while loop is not a isochronous pipe,
> iso_buffer still holds the previously deallocated buffer address and
> kfree tries to free wrong buffer address.
>
> Fixes: ea44d190764b ("usbip: Implement SG support to vhci-hcd and stub driver")
> Reported-by: kbuild test robot <lkp@xxxxxxxxx>
> Reported-by: Julia Lawall <julia.lawall@xxxxxxx>
> Signed-off-by: Suwan Kim <suwan.kim027@xxxxxxxxx>
Reviewed-by: Julia Lawall <julia.lawall@xxxxxxx>
> ---
> v1 - v2: Move the setting NULL after kfree() and add the comment
> ---
> drivers/usb/usbip/vhci_tx.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/drivers/usb/usbip/vhci_tx.c b/drivers/usb/usbip/vhci_tx.c
> index c3803785f6ef..0ae40a13a9fe 100644
> --- a/drivers/usb/usbip/vhci_tx.c
> +++ b/drivers/usb/usbip/vhci_tx.c
> @@ -147,7 +147,10 @@ static int vhci_send_cmd_submit(struct vhci_device *vdev)
> }
>
> kfree(iov);
> + /* This is only for isochronous case */
> kfree(iso_buffer);
> + iso_buffer = NULL;
> +
> usbip_dbg_vhci_tx("send txdata\n");
>
> total_size += txsize;
> --
> 2.20.1
>
>
