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 C89A2C433E0 for ; Tue, 26 May 2020 19:24:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A759720776 for ; Tue, 26 May 2020 19:24:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1590521079; bh=L9dEFwmMPW+AV5IScBr/9bkG1sG4655gjTPtCJQfpNQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=mjmiTVZfgBmIshHM6F+DoQskmMZ2/dDiPD8XdL5wYOCoGznjf/7QZjnjkUIWXkO7l la9sX60A3ZJRIy8MRTQJPZ5Y3+HCQL9UvuUB59WDPSht6xboxa1WFlbw9VN7vG8hKy hd9H9+GzTyEIZSuPf2YEsUIqORbS2SR5H/PJsab4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2392473AbgEZTYi (ORCPT ); Tue, 26 May 2020 15:24:38 -0400 Received: from mail.kernel.org ([198.145.29.99]:36288 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2391289AbgEZTHe (ORCPT ); Tue, 26 May 2020 15:07:34 -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 0E36820873; Tue, 26 May 2020 19:07:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1590520053; bh=L9dEFwmMPW+AV5IScBr/9bkG1sG4655gjTPtCJQfpNQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=GewzSnvm4cWRP71bYyVWcDUhco1aFKoVtA4sHwX1yGL9Mkc+nzUyl4p51IbNL11MM upCKfEL7N3+zWg3TDHtWOjlsRAzd7gyCkOxy4IyKOsfadA9m2C45d3txAPlcECkbS5 YgC76gqtxs/J50bOq6FVVeKvRmoyk3aKkzo4kwc4= 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 5.4 041/111] USB: core: Fix misleading driver bug report Date: Tue, 26 May 2020 20:52:59 +0200 Message-Id: <20200526183936.834497087@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200526183932.245016380@linuxfoundation.org> References: <20200526183932.245016380@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 02eaac7e1e34..a1ac2f0723b0 100644 --- a/drivers/usb/core/message.c +++ b/drivers/usb/core/message.c @@ -1143,11 +1143,11 @@ 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