linux-kernel - Re: [PATCH] HID: roccat: Fixing race condition on initialization

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: <1283033507.8037.14.camel@neuromancer>
Date:	Sun, 29 Aug 2010 00:11:47 +0200
From:	Stefan Achatz <erazor_de@...rs.sourceforge.net>
To:	Jiri Slaby <jirislaby@...il.com>
Cc:	Jiri Kosina <jkosina@...e.cz>,
	Stephen Rothwell <sfr@...b.auug.org.au>,
	linux-input@...r.kernel.org, Tejun Heo <tj@...nel.org>,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH] HID: roccat: Fixing race condition on initialization

Am Samstag, den 28.08.2010, 20:18 +0200 schrieb Jiri Slaby:
> On 08/28/2010 02:57 PM, Stefan Achatz wrote:
> > Fixed raced condition where event occurs before drvdata is set.
> > 
> > Signed-off-by: Stefan Achatz <erazor_de@...rs.sourceforge.net>
> > ---
> >  drivers/hid/hid-roccat-kone.c |    4 ++++
> >  1 files changed, 4 insertions(+), 0 deletions(-)
> > 
> > diff --git a/drivers/hid/hid-roccat-kone.c b/drivers/hid/hid-roccat-kone.c
> > index f776957..cfeab56 100644
> > --- a/drivers/hid/hid-roccat-kone.c
> > +++ b/drivers/hid/hid-roccat-kone.c
> > @@ -966,6 +966,10 @@ static int kone_raw_event(struct hid_device *hdev, struct hid_report *report,
> >  	struct kone_device *kone = hid_get_drvdata(hdev);
> >  	struct kone_mouse_event *event = (struct kone_mouse_event *)data;
> >  
> > +	/* possible race condition on initialization */
> > +	if (!kone)
> > +		return 0;
> 
> This kind of "protection" caused much headache in the tty layer in the
> past. If there is such a problem, please fix the initialization code
> instead.
> 
> What sort of problems you are seeing?
> 
> thanks,

After investigating and now fully understanding the issue I want to draw
back this patch.
The issue was no race condition in the first place, but an erroneous
code I wrote for another mouse. This is a injudicious crossport of a
half baked fix for code that didn't suffer from the problem because the
next 3 lines already do the right thing for this case.
Sorry.

--
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/