| Message ID | 20191018133516.12606-1-linux@roeck-us.net (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] ath10k: Fix a NULL-ptr-deref bug in ath10k_usb_alloc_urb_from_pipe | expand |
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
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++;