Subject: Re: [PATCH v2] ath10k: Fix a NULL-ptr-deref bug in ath10k_usb_alloc_urb_from_pipe

From: Kalle Valo <[email-masked]>
Date: Tue, 22 Oct 2019 08:37:51 +0000 (UTC)

Guenter Roeck <[email-masked]> 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 <[email-masked]>
> Reported-by: Hui Peng <[email-masked]>
> Reported-by: Mathias Payer <[email-masked]>
> Reviewed-by: Greg Kroah-Hartman <[email-masked]>
> [groeck: Add driver tag to subject, fix build warning]
> Signed-off-by: Guenter Roeck <[email-masked]>
> Signed-off-by: Kalle Valo <[email-masked]>

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