Re: [PATCH] usbip: Fix free of unallocated memory in vhci tx
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 > > > Reported-by: Julia Lawall > > > Signed-off-by: Suwan Kim > > > --- > > > 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
Re: [PATCH] usbip: Fix free of unallocated memory in vhci tx
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 Reported-by: Julia Lawall Signed-off-by: Suwan Kim --- 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
Re: [PATCH] usbip: Fix free of unallocated memory in vhci tx
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
> Reported-by: Julia Lawall
> Signed-off-by: Suwan Kim
> ---
> 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.
julia
>
> usbip_dbg_vhci_tx("setup txdata urb seqnum %lu\n",
> priv->seqnum);
> --
> 2.21.0
>
>
[PATCH] usbip: Fix free of unallocated memory in vhci tx
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
Reported-by: Julia Lawall
Signed-off-by: Suwan Kim
---
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;
usbip_dbg_vhci_tx("setup txdata urb seqnum %lu\n",
priv->seqnum);
--
2.21.0
