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.
thanks,
-- Shuah
