linux-kernel - Re: [v3.11][Regression] HID: hyperv: convert alloc+memcpy to memdup

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

Message-ID: <52432152.3030100@canonical.com>
Date:	Wed, 25 Sep 2013 13:45:54 -0400
From:	Joseph Salisbury <joseph.salisbury@...onical.com>
To:	Jiri Kosina <jkosina@...e.cz>
CC:	Dan Carpenter <dan.carpenter@...cle.com>, thomas@...3r.de,
	list@...osl.org, Haiyang Zhang <haiyangz@...rosoft.com>,
	LKML <linux-kernel@...r.kernel.org>, open@...osl.org,
	HID CORE LAYER <linux-input@...r.kernel.org>,
	devel@...uxdriverproject.org
Subject: Re: [v3.11][Regression] HID: hyperv: convert alloc+memcpy to memdup

On 09/24/2013 05:29 AM, Jiri Kosina wrote:
> On Mon, 16 Sep 2013, Joseph Salisbury wrote:
>
>>>> Can you explain a little further?  Mark commit a4a23f6 as bad?  An
>>>> initial bisect already reported that was the first bad commit, so it
>>>> can't be marked bad.  The oops on memcpy() happens after commit a4a23f6
>>>> is reverted.  The oops on memcpy() did not happen before a4a23f6 was
>>>> committed, so I assume this new oops was introduced by a change later.
>>>>
>>>> Right now I'm bisecting down the oops on memcpy() by updating the bisect
>>>> with good or bad, depending if the test kernel hit the oops.  I then
>>>> revert a4a23f6, so that revert is the HEAD of the tree each time before
>>>> building the kernel again(As long as the commit spit out by bisect is
>>>> after when a4a23f6 was introduced).
>>> Yep.  Please continue bisecting the memcpy() oops.
>>>
>>> kmemdup() is just a kzalloc() followed by a memcpy().  When we split it
>>> apart by reverting the patch then we would expect the oops to move to
>>> the memcpy() part.  Somehow "desc" is a bogus pointer, but I don't
>>> immediately see how that is possible.
>>>
>>> regards,
>>> dan carpenter
>> Thanks for the details.  We'll continue the bisect and let you know how
>> it goes.
> Did this please yield any useful result?
>
> Thanks,
>

After further testing reverting the following commit does in fact
resolve the bug:

commit b1a1442a23776756b254b69786848a94d92445ba
Author: Jiri Kosina <jkosina@...e.cz>
Date: Mon Jun 3 11:27:48 2013 +0200

    HID: core: fix reporting of raw events

Reverting this commit in v3.12-rc2 prevents the system from locking up, which happens when connecting a bluetooth trackpad.

Jiri,  do you think we should revert this patch, or is there some further debugging/data collecting you would like to do?

Thanks,

Joe



--
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/