linux-kernel - Re: [RFC/PATCH] usb/xhci: avoid kernel panic on xhci

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <530754BE.5090301@linux.intel.com>
Date:	Fri, 21 Feb 2014 15:29:34 +0200
From:	Mathias Nyman <mathias.nyman@...ux.intel.com>
To:	David Cohen <david.a.cohen@...ux.intel.com>
CC:	Alan Stern <stern@...land.harvard.edu>,
	Greg KH <gregkh@...uxfoundation.org>,
	sarah.a.sharp@...ux.intel.com, linux-usb@...r.kernel.org,
	linux-kernel@...r.kernel.org, jianqian <jianqiang.tang@...el.com>
Subject: Re: [RFC/PATCH] usb/xhci: avoid kernel panic on xhci_suspend()

On 01/08/2014 09:53 PM, David Cohen wrote:
> On Wed, Jan 08, 2014 at 10:48:06AM -0500, Alan Stern wrote:
>> On Tue, 7 Jan 2014, Greg KH wrote:
>>
>>> On Tue, Jan 07, 2014 at 05:44:26PM -0800, David Cohen wrote:
>>>> From: jianqian <jianqiang.tang@...el.com>
>>>>
>>>> There is a possible kernel panic faced on xhci_suspend().
>>>> Due to kernel modified the hub autosupend_delay to 0s, after usb1 root
>>>> hub finishes initialization, it will trigger runtime_suspend and then
>>>> it will trigger xhci runtime suspend. But at that time, if
>>>> xhci->shared_hcd is still doing initialization, it is possible to face
>>>> null pointer kernel panic in xhci_suspend() function.
>>>>
>>>> This patch checks if xhci->shared_hcd is null to avoid panic.
>>>
>>> That sounds like this is a race that should be fixed properly, not just
>>> papered over, right?
>>
>> That was my reaction too.  The best way to solve the problem is to
>> prevent the USB-2 root hub from suspending until after the USB-3 root
>> hub has been registered.
>
> That makes sense. Thanks for the feedback.
> I'll check for a new approach.
>

Could you check if this patch works for you?:

http://marc.info/?l=linux-usb&m=139298822514995&w=2

I'm not able to reproduce the original issue myself

-Mathias
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/