From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-pl1-x641.google.com ([2607:f8b0:4864:20::641]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1iLSPa-0006Az-6S for ath10k@lists.infradead.org; Fri, 18 Oct 2019 13:35:23 +0000 Received: by mail-pl1-x641.google.com with SMTP id u12so2855022pls.12 for ; Fri, 18 Oct 2019 06:35:21 -0700 (PDT) From: Guenter Roeck Subject: [PATCH v2] ath10k: Fix a NULL-ptr-deref bug in ath10k_usb_alloc_urb_from_pipe Date: Fri, 18 Oct 2019 06:35:16 -0700 Message-Id: <20191018133516.12606-1-linux@roeck-us.net> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "ath10k" Errors-To: ath10k-bounces+kvalo=adurom.com@lists.infradead.org To: Kalle Valo Cc: netdev@vger.kernel.org, linux-wireless@vger.kernel.org, linux-kernel@vger.kernel.org, ath10k@lists.infradead.org, Hui Peng , Guenter Roeck From: Hui Peng 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 Reported-by: Hui Peng Reported-by: Mathias Payer Reviewed-by: Greg Kroah-Hartman [groeck: Add driver tag to subject, fix build warning] Signed-off-by: Guenter Roeck --- 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 _______________________________________________ ath10k mailing list ath10k@lists.infradead.org http://lists.infradead.org/mailman/listinfo/ath10k