* [PATCH] usbip: Fix free of unallocated memory in vhci tx
@ 2019-10-21 14:24 Suwan Kim
2019-10-21 15:08 ` Julia Lawall
0 siblings, 1 reply; 4+ messages in thread
From: Suwan Kim @ 2019-10-21 14:24 UTC (permalink / raw)
To: shuah, gregkh
Cc: linux-kernel, linux-usb, julia.lawall, valentina.manea.m,
Suwan Kim, kbuild test robot
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@intel.com>
Reported-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Suwan Kim <suwan.kim027@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;
usbip_dbg_vhci_tx("setup txdata urb seqnum %lu\n",
priv->seqnum);
--
2.21.0
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH] usbip: Fix free of unallocated memory in vhci tx
2019-10-21 14:24 [PATCH] usbip: Fix free of unallocated memory in vhci tx Suwan Kim
@ 2019-10-21 15:08 ` Julia Lawall
2019-10-21 19:28 ` shuah
0 siblings, 1 reply; 4+ messages in thread
From: Julia Lawall @ 2019-10-21 15:08 UTC (permalink / raw)
To: Suwan Kim
Cc: shuah, gregkh, linux-kernel, linux-usb, julia.lawall,
valentina.manea.m, kbuild test robot
[-- Attachment #1: Type: text/plain, Size: 1545 bytes --]
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@intel.com>
> Reported-by: Julia Lawall <julia.lawall@lip6.fr>
> Signed-off-by: Suwan Kim <suwan.kim027@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.
julia
>
> usbip_dbg_vhci_tx("setup txdata urb seqnum %lu\n",
> priv->seqnum);
> --
> 2.21.0
>
>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] usbip: Fix free of unallocated memory in vhci tx
2019-10-21 15:08 ` Julia Lawall
@ 2019-10-21 19:28 ` shuah
2019-10-22 9:26 ` Suwan Kim
0 siblings, 1 reply; 4+ messages in thread
From: shuah @ 2019-10-21 19:28 UTC (permalink / raw)
To: Julia Lawall, Suwan Kim
Cc: gregkh, linux-kernel, linux-usb, valentina.manea.m,
kbuild test robot, shuah
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@intel.com>
>> Reported-by: Julia Lawall <julia.lawall@lip6.fr>
>> Signed-off-by: Suwan Kim <suwan.kim027@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
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] usbip: Fix free of unallocated memory in vhci tx
2019-10-21 19:28 ` shuah
@ 2019-10-22 9:26 ` Suwan Kim
0 siblings, 0 replies; 4+ messages in thread
From: Suwan Kim @ 2019-10-22 9:26 UTC (permalink / raw)
To: shuah
Cc: Julia Lawall, gregkh, linux-kernel, linux-usb, valentina.manea.m,
kbuild test robot
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@intel.com>
> > > Reported-by: Julia Lawall <julia.lawall@lip6.fr>
> > > Signed-off-by: Suwan Kim <suwan.kim027@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.
Ok. I will send v2.
Regards
Suwan Kim
^ permalink raw reply [flat|nested] 4+ messages in thread
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2019-10-21 14:24 [PATCH] usbip: Fix free of unallocated memory in vhci tx Suwan Kim
2019-10-21 15:08 ` Julia Lawall
2019-10-21 19:28 ` shuah
2019-10-22 9:26 ` Suwan Kim
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