On Mon, Oct 21, 2019 at 01:28:54PM -0600, shuah wrote: > On 10/21/19 9:08 AM, Julia Lawall wrote: > > > > > > On Mon, 21 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> > > > --- > > > drivers/usb/usbip/vhci_tx.c | 1 + > > > 1 file changed, 1 insertion(+) > > > > > > diff --git a/drivers/usb/usbip/vhci_tx.c b/drivers/usb/usbip/vhci_tx.c > > > index c3803785f6ef..b290e810d11b 100644 > > > --- a/drivers/usb/usbip/vhci_tx.c > > > +++ b/drivers/usb/usbip/vhci_tx.c > > > @@ -73,6 +73,7 @@ static int vhci_send_cmd_submit(struct vhci_device *vdev) > > > memset(&pdu_header, 0, sizeof(pdu_header)); > > > memset(&msg, 0, sizeof(msg)); > > > memset(&iov, 0, sizeof(iov)); > > > + iso_buffer = NULL; > > > > Somehow I would have put it after the kfree, since the kfree makes the > > value invalid. iso_buffer is already initialized to NULL for the first > > iteration. If you want to put the setting to NULL at the top of the loop, > > maybe the = NULL in the first line should be removed. > > > > It makes sense to clear it after kfree() on line 150. > > This kfree() and clearing iso_buffer are necessary only for > PIPE_ISOCHRONOUS case. > > Please add a comment above that this is for isoc case. Ok. I will send v2. Regards Suwan Kim
