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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id F107CC433EF for ; Thu, 21 Apr 2022 10:07:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1388104AbiDUKKc (ORCPT ); Thu, 21 Apr 2022 06:10:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35616 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1354947AbiDUKKc (ORCPT ); Thu, 21 Apr 2022 06:10:32 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 86474286D7; Thu, 21 Apr 2022 03:07:42 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 3BA22B8233A; Thu, 21 Apr 2022 10:07:41 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 784B0C385A1; Thu, 21 Apr 2022 10:07:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1650535659; bh=4uQ8r3mXhXLd76TxIbpDEIMJezspVHkacQKu5lK2eg8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=zgUsSRLpb/S0iggDZD/Wh6rIYeGUazairYpYXKd50h7p7R11HU2s5O9Kz7M33veOi MJUfbz0nA0NRARHhGOvOrQMUM9vBp2OwR9jChZULqGqYgQDWQhixrJmslQ7O2JHrst 6OGsW11hBs/vMtqmn91MmlXvJinN8e2/H0hX/bBY= Date: Thu, 21 Apr 2022 12:07:36 +0200 From: Greg KH To: Zixuan Fu Cc: mathias.nyman@intel.com, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, baijiaju1990@gmail.com, TOTE Robot Subject: Re: [PATCH] drivers: usb: host: fix NULL pointer dereferences triggered by unhandled errors in xhci_create_rhub_port_array() Message-ID: References: <20220421094236.1052170-1-r33s3n6@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220421094236.1052170-1-r33s3n6@gmail.com> Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org On Thu, Apr 21, 2022 at 05:42:36PM +0800, Zixuan Fu wrote: > In xhci_create_rhub_port_array(), when rhub->num_ports is zero, > rhub->ports would not be set; when kcalloc_node() fails, rhub->ports > would be set to NULL. In these two cases, xhci_create_rhub_port_array() > just returns void, and thus its callers are unaware of the error. > > Then rhub->ports is dereferenced in xhci_usb3_hub_descriptor() or > xhci_usb2_hub_descriptor(). > > To fix the bug, xhci_setup_port_arrays() should return an integer to > indicate a possible error, and its callers should handle the error. > > Here is the log when this bug occurred in our fault-injection testing: > > [ 24.001309] BUG: kernel NULL pointer dereference, address: 0000000000000000 > ... > [ 24.003992] RIP: 0010:xhci_hub_control+0x3f5/0x60d0 [xhci_hcd] > ... > [ 24.009803] Call Trace: > [ 24.010014] > [ 24.011310] usb_hcd_submit_urb+0x1233/0x1fd0 > [ 24.017071] usb_start_wait_urb+0x115/0x310 > [ 24.017641] usb_control_msg+0x28a/0x450 > [ 24.019046] hub_probe+0xb16/0x2320 > [ 24.019757] usb_probe_interface+0x4f1/0x930 > [ 24.019765] really_probe+0x33d/0x970 > [ 24.019768] __driver_probe_device+0x157/0x210 > [ 24.019772] driver_probe_device+0x4f/0x340 > [ 24.019775] __device_attach_driver+0x2ee/0x3a0 > ... > > Reported-by: TOTE Robot > Signed-off-by: Zixuan Fu > --- > drivers/usb/host/xhci-mem.c | 17 ++++++++++++----- > 1 file changed, 12 insertions(+), 5 deletions(-) > > diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c > index bbb27ee2c6a3..024515346c39 100644 > --- a/drivers/usb/host/xhci-mem.c > +++ b/drivers/usb/host/xhci-mem.c > @@ -2235,7 +2235,7 @@ static void xhci_add_in_port(struct xhci_hcd *xhci, unsigned int num_ports, > /* FIXME: Should we disable ports not in the Extended Capabilities? */ > } > > -static void xhci_create_rhub_port_array(struct xhci_hcd *xhci, > +static int xhci_create_rhub_port_array(struct xhci_hcd *xhci, > struct xhci_hub *rhub, gfp_t flags) > { > int port_index = 0; > @@ -2243,11 +2243,11 @@ static void xhci_create_rhub_port_array(struct xhci_hcd *xhci, > struct device *dev = xhci_to_hcd(xhci)->self.sysdev; > > if (!rhub->num_ports) > - return; > + return -EINVAL; > rhub->ports = kcalloc_node(rhub->num_ports, sizeof(*rhub->ports), > flags, dev_to_node(dev)); > if (!rhub->ports) > - return; > + return -ENOMEM; > > for (i = 0; i < HCS_MAX_PORTS(xhci->hcs_params1); i++) { > if (xhci->hw_ports[i].rhub != rhub || > @@ -2259,6 +2259,7 @@ static void xhci_create_rhub_port_array(struct xhci_hcd *xhci, > if (port_index == rhub->num_ports) > break; > } > + return 0; > } > > /* > @@ -2277,6 +2278,7 @@ static int xhci_setup_port_arrays(struct xhci_hcd *xhci, gfp_t flags) > int cap_count = 0; > u32 cap_start; > struct device *dev = xhci_to_hcd(xhci)->self.sysdev; > + int ret; > > num_ports = HCS_MAX_PORTS(xhci->hcs_params1); > xhci->hw_ports = kcalloc_node(num_ports, sizeof(*xhci->hw_ports), > @@ -2367,8 +2369,13 @@ static int xhci_setup_port_arrays(struct xhci_hcd *xhci, gfp_t flags) > * Not sure how the USB core will handle a hub with no ports... > */ > > - xhci_create_rhub_port_array(xhci, &xhci->usb2_rhub, flags); > - xhci_create_rhub_port_array(xhci, &xhci->usb3_rhub, flags); > + ret = xhci_create_rhub_port_array(xhci, &xhci->usb2_rhub, flags); > + if (ret) > + return ret; > + > + ret = xhci_create_rhub_port_array(xhci, &xhci->usb3_rhub, flags); > + if (ret) > + return ret; What about the memory allocated by the first call to xhci_create_rhub_port_array()? Is that now lost? Same for everything else allocated before these calls, how is that cleaned up properly? thanks, greg k-h