The `ar_usb` field of `ath6kl_usb_pipe_usb_pipe` objects
are initialized to point to the containing `ath6kl_usb` object
according to endpoint descriptors read from the device side, as shown
below in `ath6kl_usb_setup_pipe_resources`:
for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
endpoint = &iface_desc->endpoint[i].desc;
// get the address from endpoint descriptor
pipe_num = ath6kl_usb_get_logical_pipe_num(ar_usb,
endpoint->bEndpointAddress,
&urbcount);
......
// select the pipe object
pipe = &ar_usb->pipes[pipe_num];
// initialize the ar_usb field
pipe->ar_usb = ar_usb;
}
The driver assumes that the addresses reported in endpoint
descriptors from device side to be complete. If a device is
malicious and does not report complete addresses, it may trigger
NULL-ptr-deref `ath6kl_usb_alloc_urb_from_pipe` and
`ath6kl_usb_free_urb_to_pipe`.
This patch fixes the bug by preventing potential NULL-ptr-deref.
Signed-off-by: Hui Peng <[email protected]>
Reported-by: Hui Peng <[email protected]>
Reported-by: Mathias Payer <[email protected]>
---
drivers/net/wireless/ath/ath6kl/usb.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/drivers/net/wireless/ath/ath6kl/usb.c b/drivers/net/wireless/ath/ath6kl/usb.c
index 4defb7a0330f..53b66e9434c9 100644
--- a/drivers/net/wireless/ath/ath6kl/usb.c
+++ b/drivers/net/wireless/ath/ath6kl/usb.c
@@ -132,6 +132,10 @@ ath6kl_usb_alloc_urb_from_pipe(struct ath6kl_usb_pipe *pipe)
struct ath6kl_urb_context *urb_context = NULL;
unsigned long flags;
+ /* bail if this pipe is not initialized */
+ if (!pipe->ar_usb)
+ return NULL;
+
spin_lock_irqsave(&pipe->ar_usb->cs_lock, flags);
if (!list_empty(&pipe->urb_list_head)) {
urb_context =
@@ -150,6 +154,10 @@ static void ath6kl_usb_free_urb_to_pipe(struct ath6kl_usb_pipe *pipe,
{
unsigned long flags;
+ /* bail if this pipe is not initialized */
+ if (!pipe->ar_usb)
+ return;
+
spin_lock_irqsave(&pipe->ar_usb->cs_lock, flags);
pipe->urb_cnt++;
--
2.22.0
On Sat, Aug 03, 2019 at 08:29:04PM -0400, Hui Peng wrote:
> The `ar_usb` field of `ath6kl_usb_pipe_usb_pipe` objects
> are initialized to point to the containing `ath6kl_usb` object
> according to endpoint descriptors read from the device side, as shown
> below in `ath6kl_usb_setup_pipe_resources`:
>
> for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
> endpoint = &iface_desc->endpoint[i].desc;
>
> // get the address from endpoint descriptor
> pipe_num = ath6kl_usb_get_logical_pipe_num(ar_usb,
> endpoint->bEndpointAddress,
> &urbcount);
> ......
> // select the pipe object
> pipe = &ar_usb->pipes[pipe_num];
>
> // initialize the ar_usb field
> pipe->ar_usb = ar_usb;
> }
>
> The driver assumes that the addresses reported in endpoint
> descriptors from device side to be complete. If a device is
> malicious and does not report complete addresses, it may trigger
> NULL-ptr-deref `ath6kl_usb_alloc_urb_from_pipe` and
> `ath6kl_usb_free_urb_to_pipe`.
>
> This patch fixes the bug by preventing potential NULL-ptr-deref.
>
> Signed-off-by: Hui Peng <[email protected]>
> Reported-by: Hui Peng <[email protected]>
> Reported-by: Mathias Payer <[email protected]>
Reviewed-by: Greg Kroah-Hartman <[email protected]>
Guenter Roeck <[email protected]> writes:
> On Sat, Aug 03, 2019 at 08:29:04PM -0400, Hui Peng wrote:
>> The `ar_usb` field of `ath6kl_usb_pipe_usb_pipe` objects
>> are initialized to point to the containing `ath6kl_usb` object
>> according to endpoint descriptors read from the device side, as shown
>> below in `ath6kl_usb_setup_pipe_resources`:
>>
>> for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
>> endpoint = &iface_desc->endpoint[i].desc;
>>
>> // get the address from endpoint descriptor
>> pipe_num = ath6kl_usb_get_logical_pipe_num(ar_usb,
>> endpoint->bEndpointAddress,
>> &urbcount);
>> ......
>> // select the pipe object
>> pipe = &ar_usb->pipes[pipe_num];
>>
>> // initialize the ar_usb field
>> pipe->ar_usb = ar_usb;
>> }
>>
>> The driver assumes that the addresses reported in endpoint
>> descriptors from device side to be complete. If a device is
>> malicious and does not report complete addresses, it may trigger
>> NULL-ptr-deref `ath6kl_usb_alloc_urb_from_pipe` and
>> `ath6kl_usb_free_urb_to_pipe`.
>>
>> This patch fixes the bug by preventing potential NULL-ptr-deref.
>>
>> Signed-off-by: Hui Peng <[email protected]>
>> Reported-by: Hui Peng <[email protected]>
>> Reported-by: Mathias Payer <[email protected]>
>
> I don't see this patch in the upstream kernel or in -next.
>
> At the same time, it is supposed to fix CVE-2019-15098, which has
> a CVSS v2.0 score of 7.8 (high).
>
> Is this patch going to be applied to the upstream kernel ?
Lately I have been very busy and I have not had a chance to apply ath6kl
nor ath10k patches. This patch is on my queue and my plan is to go
through my patch queue next week.
--
https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
Hui Peng <[email protected]> writes:
> The reason that this patch is still in the pending state is that it
> has not reviewed by maintainers (they are not responding).
> @Greg: can we apply it?
Who is "we" in this case? But anyway, I'll review the patch and if it's
ok I'll take it through my ath.git tree, as normal.
--
https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
Hui Peng <[email protected]> wrote:
> The `ar_usb` field of `ath6kl_usb_pipe_usb_pipe` objects
> are initialized to point to the containing `ath6kl_usb` object
> according to endpoint descriptors read from the device side, as shown
> below in `ath6kl_usb_setup_pipe_resources`:
>
> for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
> endpoint = &iface_desc->endpoint[i].desc;
>
> // get the address from endpoint descriptor
> pipe_num = ath6kl_usb_get_logical_pipe_num(ar_usb,
> endpoint->bEndpointAddress,
> &urbcount);
> ......
> // select the pipe object
> pipe = &ar_usb->pipes[pipe_num];
>
> // initialize the ar_usb field
> pipe->ar_usb = ar_usb;
> }
>
> The driver assumes that the addresses reported in endpoint
> descriptors from device side to be complete. If a device is
> malicious and does not report complete addresses, it may trigger
> NULL-ptr-deref `ath6kl_usb_alloc_urb_from_pipe` and
> `ath6kl_usb_free_urb_to_pipe`.
>
> This patch fixes the bug by preventing potential NULL-ptr-deref
> (CVE-2019-15098).
>
> Signed-off-by: Hui Peng <[email protected]>
> Reported-by: Hui Peng <[email protected]>
> Reported-by: Mathias Payer <[email protected]>
> Reviewed-by: Greg Kroah-Hartman <[email protected]>
> Signed-off-by: Kalle Valo <[email protected]>
Patch applied to ath-next branch of ath.git, thanks.
39d170b3cb62 ath6kl: fix a NULL-ptr-deref bug in ath6kl_usb_alloc_urb_from_pipe()
--
https://patchwork.kernel.org/patch/11074655/
https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches