From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D56D7C43331 for ; Tue, 12 Nov 2019 23:51:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B4BAC214E0 for ; Tue, 12 Nov 2019 23:51:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727352AbfKLXvK (ORCPT ); Tue, 12 Nov 2019 18:51:10 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:57352 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727015AbfKLXug (ORCPT ); Tue, 12 Nov 2019 18:50:36 -0500 Received: from [167.98.27.226] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1iUfvd-0008IN-WE; Tue, 12 Nov 2019 23:50:34 +0000 Received: from ben by deadeye with local (Exim 4.93-RC1) (envelope-from ) id 1iUfvc-00057c-SZ; Tue, 12 Nov 2019 23:50:32 +0000 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, Denis Kirjanov , "Mathias Payer" , "Hui Peng" , "Kalle Valo" , "Greg Kroah-Hartman" Date: Tue, 12 Nov 2019 23:48:13 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 16/25] ath6kl: fix a NULL-ptr-deref bug in ath6kl_usb_alloc_urb_from_pipe() In-Reply-To: X-SA-Exim-Connect-IP: 167.98.27.226 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.77-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Hui Peng commit 39d170b3cb62ba98567f5c4f40c27b5864b304e5 upstream. 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 Reported-by: Hui Peng Reported-by: Mathias Payer Reviewed-by: Greg Kroah-Hartman Signed-off-by: Kalle Valo Signed-off-by: Ben Hutchings --- drivers/net/wireless/ath/ath6kl/usb.c | 8 ++++++++ 1 file changed, 8 insertions(+) --- 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 at 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( { 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++;