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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 88408C433E0 for ; Tue, 26 May 2020 18:56:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 64EC6208B8 for ; Tue, 26 May 2020 18:56:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1590519397; bh=yxPt5RtTF67o4Bq8gMPe8OYSr0m+EJyUcIQGpD7elm4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=A0JD+rrirQoZGLW5ICie1q1at3W5kx7EGpbJ/zrODLAg3w8G8ucJkOuLoR2mnHLuY Psa5XcgGWzr9NAMFGIh1Z1CDTz6+Db494CYbyPdYcbD7B4S+R6RVyDkBMuIfld3Th8 QGllf/Wi26NblQi1dXsPUyUkREg61hgIpGuUSm5o= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389884AbgEZS4g (ORCPT ); Tue, 26 May 2020 14:56:36 -0400 Received: from mail.kernel.org ([198.145.29.99]:49426 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389868AbgEZS4d (ORCPT ); Tue, 26 May 2020 14:56:33 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (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 D7C0521501; Tue, 26 May 2020 18:56:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1590519393; bh=yxPt5RtTF67o4Bq8gMPe8OYSr0m+EJyUcIQGpD7elm4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=uZECACFXyMpzGM+1eb06Xtzy6bB1NPb+oaPAohfFAVUsyUdm9IolS4qr1bCgikSEb wTQJkUIWcGJ0ZLT9NK7SXeJPt6bjRiC9HYNDcwLdtuz1FnIPOlqEAJC529eSphvThG y6pSczg2himKXOfvxFXi/+8VhaFeFy6Guo0Dkv3Q= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Alan Stern , Sasha Levin , syzbot+db339689b2101f6f6071@syzkaller.appspotmail.com Subject: [PATCH 4.4 10/65] USB: core: Fix misleading driver bug report Date: Tue, 26 May 2020 20:52:29 +0200 Message-Id: <20200526183910.004128091@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200526183905.988782958@linuxfoundation.org> References: <20200526183905.988782958@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: Alan Stern [ Upstream commit ac854131d9844f79e2fdcef67a7707227538d78a ] The syzbot fuzzer found a race between URB submission to endpoint 0 and device reset. Namely, during the reset we call usb_ep0_reinit() because the characteristics of ep0 may have changed (if the reset follows a firmware update, for example). While usb_ep0_reinit() is running there is a brief period during which the pointers stored in udev->ep_in[0] and udev->ep_out[0] are set to NULL, and if an URB is submitted to ep0 during that period, usb_urb_ep_type_check() will report it as a driver bug. In the absence of those pointers, the routine thinks that the endpoint doesn't exist. The log message looks like this: ------------[ cut here ]------------ usb 2-1: BOGUS urb xfer, pipe 2 != type 2 WARNING: CPU: 0 PID: 9241 at drivers/usb/core/urb.c:478 usb_submit_urb+0x1188/0x1460 drivers/usb/core/urb.c:478 Now, although submitting an URB while the device is being reset is a questionable thing to do, it shouldn't count as a driver bug as severe as submitting an URB for an endpoint that doesn't exist. Indeed, endpoint 0 always exists, even while the device is in its unconfigured state. To prevent these misleading driver bug reports, this patch updates usb_disable_endpoint() to avoid clearing the ep_in[] and ep_out[] pointers when the endpoint being disabled is ep0. There's no danger of leaving a stale pointer in place, because the usb_host_endpoint structure being pointed to is stored permanently in udev->ep0; it doesn't get deallocated until the entire usb_device structure does. Reported-and-tested-by: syzbot+db339689b2101f6f6071@syzkaller.appspotmail.com Signed-off-by: Alan Stern Link: https://lore.kernel.org/r/Pine.LNX.4.44L0.2005011558590.903-100000@netrider.rowland.org Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/usb/core/message.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c index 747343c61398..f083ecfddd1b 100644 --- a/drivers/usb/core/message.c +++ b/drivers/usb/core/message.c @@ -1080,11 +1080,11 @@ void usb_disable_endpoint(struct usb_device *dev, unsigned int epaddr, if (usb_endpoint_out(epaddr)) { ep = dev->ep_out[epnum]; - if (reset_hardware) + if (reset_hardware && epnum != 0) dev->ep_out[epnum] = NULL; } else { ep = dev->ep_in[epnum]; - if (reset_hardware) + if (reset_hardware && epnum != 0) dev->ep_in[epnum] = NULL; } if (ep) { -- 2.25.1