* [PATCH v2] ath10k: Fix a NULL-ptr-deref bug in ath10k_usb_alloc_urb_from_pipe
@ 2019-10-18 13:35 Guenter Roeck
2019-10-22 8:37 ` Kalle Valo
0 siblings, 1 reply; 2+ messages in thread
From: Guenter Roeck @ 2019-10-18 13:35 UTC (permalink / raw)
To: Kalle Valo
Cc: ath10k, linux-wireless, netdev, linux-kernel, Hui Peng, Guenter Roeck
From: Hui Peng <benquike@gmail.com>
The `ar_usb` field of `ath10k_usb_pipe_usb_pipe` objects
are initialized to point to the containing `ath10k_usb` object
according to endpoint descriptors read from the device side, as shown
below in `ath10k_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 = ath10k_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 `ath10k_usb_alloc_urb_from_pipe` and
`ath10k_usb_free_urb_to_pipe`.
This patch fixes the bug by preventing potential NULL-ptr-deref.
Signed-off-by: Hui Peng <benquike@gmail.com>
Reported-by: Hui Peng <benquike@gmail.com>
Reported-by: Mathias Payer <mathias.payer@nebelwelt.net>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[groeck: Add driver tag to subject, fix build warning]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
v2: Fix build warning, add "ath10k:" to subject
drivers/net/wireless/ath/ath10k/usb.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/drivers/net/wireless/ath/ath10k/usb.c b/drivers/net/wireless/ath/ath10k/usb.c
index e1420f67f776..9ebe74ee4aef 100644
--- a/drivers/net/wireless/ath/ath10k/usb.c
+++ b/drivers/net/wireless/ath/ath10k/usb.c
@@ -38,6 +38,10 @@ ath10k_usb_alloc_urb_from_pipe(struct ath10k_usb_pipe *pipe)
struct ath10k_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 = list_first_entry(&pipe->urb_list_head,
@@ -55,6 +59,10 @@ static void ath10k_usb_free_urb_to_pipe(struct ath10k_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++;
--
2.17.1
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH v2] ath10k: Fix a NULL-ptr-deref bug in ath10k_usb_alloc_urb_from_pipe
2019-10-18 13:35 [PATCH v2] ath10k: Fix a NULL-ptr-deref bug in ath10k_usb_alloc_urb_from_pipe Guenter Roeck
@ 2019-10-22 8:37 ` Kalle Valo
0 siblings, 0 replies; 2+ messages in thread
From: Kalle Valo @ 2019-10-22 8:37 UTC (permalink / raw)
To: Guenter Roeck
Cc: ath10k, linux-wireless, netdev, linux-kernel, Hui Peng, Guenter Roeck
Guenter Roeck <linux@roeck-us.net> wrote:
> The `ar_usb` field of `ath10k_usb_pipe_usb_pipe` objects
> are initialized to point to the containing `ath10k_usb` object
> according to endpoint descriptors read from the device side, as shown
> below in `ath10k_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 = ath10k_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 `ath10k_usb_alloc_urb_from_pipe` and
> `ath10k_usb_free_urb_to_pipe`.
>
> This patch fixes the bug by preventing potential NULL-ptr-deref.
>
> Signed-off-by: Hui Peng <benquike@gmail.com>
> Reported-by: Hui Peng <benquike@gmail.com>
> Reported-by: Mathias Payer <mathias.payer@nebelwelt.net>
> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> [groeck: Add driver tag to subject, fix build warning]
> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
> Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Patch applied to ath-next branch of ath.git, thanks.
bfd6e6e6c5d2 ath10k: Fix a NULL-ptr-deref bug in ath10k_usb_alloc_urb_from_pipe
--
https://patchwork.kernel.org/patch/11198433/
https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
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