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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 8A3B0CA9EC9 for ; Mon, 4 Nov 2019 21:48:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5C31021655 for ; Mon, 4 Nov 2019 21:48:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1572904110; bh=5YfsL84lW/rNJVkUOyhps8l0wKXGrBYJqxZNQ+RK7Qw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=NBOHhyyIbyPf/ICgB8+uyprjLAilzp2V7EILiuK/ou0q5WSYVsBjp3ugRpmv5VyFp JwEP2XP5juTuq+vMQkQpxItBm7YVK31MRL0Qi6AvuhoDMVayV/S2DUxioP3Gp3zaI+ 2Vh+kDWx3dM+L7KxrSjUJHXhpHsXmkg8M4r7b99Q= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730036AbfKDVs3 (ORCPT ); Mon, 4 Nov 2019 16:48:29 -0500 Received: from mail.kernel.org ([198.145.29.99]:38856 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729968AbfKDVs0 (ORCPT ); Mon, 4 Nov 2019 16:48:26 -0500 Received: from localhost (6.204-14-84.ripe.coltfrance.com [84.14.204.6]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id B2DE520B7C; Mon, 4 Nov 2019 21:48:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1572904106; bh=5YfsL84lW/rNJVkUOyhps8l0wKXGrBYJqxZNQ+RK7Qw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ObRKM8K8ql9X8RhzfGvcsoMdJhWnsNugbsbZYyQkPoilyqhK5gIZwevDZ7gZyGoZS YEQzZcVyX62XAgVvUZ7yQ3pzCRiEmlmEBL4nfjawRGrc781xmUNwWEEhaxpembh9nb kYPAVEgkS58hwPpgyOdc+2Ogy21bybSTOGBGKN2Q= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Hui Peng , Mathias Payer , Kalle Valo , Sasha Levin Subject: [PATCH 4.4 24/46] ath6kl: fix a NULL-ptr-deref bug in ath6kl_usb_alloc_urb_from_pipe() Date: Mon, 4 Nov 2019 22:44:55 +0100 Message-Id: <20191104211855.943825731@linuxfoundation.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20191104211830.912265604@linuxfoundation.org> References: <20191104211830.912265604@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Hui Peng [ Upstream commit 39d170b3cb62ba98567f5c4f40c27b5864b304e5 ] 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: Sasha Levin --- 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++;