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 <l...@intel.com> Reported-by: Julia Lawall <julia.law...@lip6.fr> Signed-off-by: Suwan Kim <suwan.kim...@gmail.com> --- 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. thanks, -- Shuah
