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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 D7EB7C433E0 for ; Thu, 14 May 2020 18:55:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9A01E2081A for ; Thu, 14 May 2020 18:55:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1589482546; bh=B/jjLS5yxQUp47SB+Cv7TQJ3NiJnGkYG/R0jVVbl/mY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=JldNAOPxwIXs9Pictb6E+7Z2AaBQ3NJw27hRPEZlAmoH6j9fQGPjfVzwmULnxIbmR kGuF99Ud8fVygNOQiLDeECATOWSvZHKdGnToZi/jr4an+Ol3qfC8R+IWvuLQT77rr3 9PTZEDW0y9l5bK1+R7kYbaXITM8RqYZVUj1lmfeU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729478AbgENSzp (ORCPT ); Thu, 14 May 2020 14:55:45 -0400 Received: from mail.kernel.org ([198.145.29.99]:56362 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729461AbgENSzo (ORCPT ); Thu, 14 May 2020 14:55:44 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 96A2C206DC; Thu, 14 May 2020 18:55:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1589482543; bh=B/jjLS5yxQUp47SB+Cv7TQJ3NiJnGkYG/R0jVVbl/mY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=o3p7iVjMadQF7Txl+8eprxMrKXYXLi63J9Mz5N5BDdOoTm5yr1CYKCh1Za64o3UQw ipN4OT6IAwBhi+G4zZkKfJsLpQ0ScfmYlycAZuxcYRj5wlo8m7vsgcj09HUpshu5ec Qx0974iRyY7+++l/SbeQNie5tWwZdKus9qVT1LRw= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Alan Stern , syzbot+db339689b2101f6f6071@syzkaller.appspotmail.com, Greg Kroah-Hartman , Sasha Levin , linux-usb@vger.kernel.org Subject: [PATCH AUTOSEL 4.14 35/39] USB: core: Fix misleading driver bug report Date: Thu, 14 May 2020 14:54:52 -0400 Message-Id: <20200514185456.21060-35-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200514185456.21060-1-sashal@kernel.org> References: <20200514185456.21060-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@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 00e80cfe614ce..298c91f83aeec 100644 --- a/drivers/usb/core/message.c +++ b/drivers/usb/core/message.c @@ -1082,11 +1082,11 @@ 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) { -- 2.20.1