From patchwork Tue Nov 23 10:16:56 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mathias Nyman X-Patchwork-Id: 12633845 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7AC12C433EF for ; Tue, 23 Nov 2021 10:15:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235368AbhKWKSx (ORCPT ); Tue, 23 Nov 2021 05:18:53 -0500 Received: from mga02.intel.com ([134.134.136.20]:51066 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235337AbhKWKSx (ORCPT ); Tue, 23 Nov 2021 05:18:53 -0500 X-IronPort-AV: E=McAfee;i="6200,9189,10176"; a="222217864" X-IronPort-AV: E=Sophos;i="5.87,257,1631602800"; d="scan'208";a="222217864" Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by orsmga101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Nov 2021 02:15:45 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.87,257,1631602800"; d="scan'208";a="590374148" Received: from mattu-haswell.fi.intel.com ([10.237.72.199]) by FMSMGA003.fm.intel.com with ESMTP; 23 Nov 2021 02:15:42 -0800 From: Mathias Nyman To: Cc: m.szyprowski@samsung.com, , kishon@ti.com, hdegoede@redhat.com, chris.chiu@canonical.com, linux-usb@vger.kernel.org, Mathias Nyman , stable@vger.kernel.org Subject: [PATCH] usb: hub: Fix locking issues with address0_mutex Date: Tue, 23 Nov 2021 12:16:56 +0200 Message-Id: <20211123101656.1113518-1-mathias.nyman@linux.intel.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org Fix the circular lock dependency and unbalanced unlock of addess0_mutex introduced when fixing an address0_mutex enumeration retry race in commit ae6dc22d2d1 ("usb: hub: Fix usb enumeration issue due to address0 race") Make sure locking order between port_dev->status_lock and address0_mutex is correct, and that address0_mutex is not unlocked in hub_port_connect "done:" codepath which may be reached without locking address0_mutex Fixes: 6ae6dc22d2d1 ("usb: hub: Fix usb enumeration issue due to address0 race") Cc: Reported-by: Marek Szyprowski Acked-by: Hans de Goede Tested-by: Hans de Goede Tested-by: Marek Szyprowski Signed-off-by: Mathias Nyman --- drivers/usb/core/hub.c | 20 ++++++++++++-------- 1 file changed, 12 insertions(+), 8 deletions(-) diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index 9f0d1af8be6f..e907dfa0ca6d 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -5190,6 +5190,7 @@ static void hub_port_connect(struct usb_hub *hub, int port1, u16 portstatus, struct usb_port *port_dev = hub->ports[port1 - 1]; struct usb_device *udev = port_dev->child; static int unreliable_port = -1; + bool retry_locked; /* Disconnect any existing devices under this port */ if (udev) { @@ -5246,10 +5247,10 @@ static void hub_port_connect(struct usb_hub *hub, int port1, u16 portstatus, status = 0; - mutex_lock(hcd->address0_mutex); - for (i = 0; i < PORT_INIT_TRIES; i++) { - + usb_lock_port(port_dev); + mutex_lock(hcd->address0_mutex); + retry_locked = true; /* reallocate for each attempt, since references * to the previous one can escape in various ways */ @@ -5257,6 +5258,8 @@ static void hub_port_connect(struct usb_hub *hub, int port1, u16 portstatus, if (!udev) { dev_err(&port_dev->dev, "couldn't allocate usb_device\n"); + mutex_unlock(hcd->address0_mutex); + usb_unlock_port(port_dev); goto done; } @@ -5278,13 +5281,13 @@ static void hub_port_connect(struct usb_hub *hub, int port1, u16 portstatus, } /* reset (non-USB 3.0 devices) and get descriptor */ - usb_lock_port(port_dev); status = hub_port_init(hub, udev, port1, i); - usb_unlock_port(port_dev); if (status < 0) goto loop; mutex_unlock(hcd->address0_mutex); + usb_unlock_port(port_dev); + retry_locked = false; if (udev->quirks & USB_QUIRK_DELAY_INIT) msleep(2000); @@ -5374,11 +5377,14 @@ static void hub_port_connect(struct usb_hub *hub, int port1, u16 portstatus, loop_disable: hub_port_disable(hub, port1, 1); - mutex_lock(hcd->address0_mutex); loop: usb_ep0_reinit(udev); release_devnum(udev); hub_free_dev(udev); + if (retry_locked) { + mutex_unlock(hcd->address0_mutex); + usb_unlock_port(port_dev); + } usb_put_dev(udev); if ((status == -ENOTCONN) || (status == -ENOTSUPP)) break; @@ -5401,8 +5407,6 @@ static void hub_port_connect(struct usb_hub *hub, int port1, u16 portstatus, } done: - mutex_unlock(hcd->address0_mutex); - hub_port_disable(hub, port1, 1); if (hcd->driver->relinquish_port && !hub->hdev->parent) { if (status != -ENOTCONN && status != -ENODEV)