Re: HIDDEV: potential NULL dereference

From: Amit Nagal
Date: Mon Sep 06 2010 - 01:33:20 EST


Hi ,

i was one of the users who informed that crash do disappears .

the reality with me is that the probability of occurence of crash
reduces significantly

but on rigourous testing crash resurfaces again .

sorry for wrong reporting .

Regards
Amit Nagal



On Sat, Sep 4, 2010 at 10:09 PM, Chris Ball <cjb@xxxxxxxxxx> wrote:
> Hi Jiri,
>
>   > If hid was ever NULL at this phase, the check couldn't improve
>   > anything due to hid->driver_data dereference being still before
>   > the check. So again my question, how this could change anything?
>   >
>   > Above that, it just makes the window shorter, but the bug is
>   > still there, isn't it? Is the following scenario reasonable?
>
> You're right -- I'd missed the other dereference, sorry.  It's
> surprising that we have two reports from users saying that the
> patch got rid of a reproducible oops for them.
>
> Dan Carpenter has commented on this too:
>   http://www.spinics.net/lists/linux-input/msg10541.html
>
> As he says, it looks like the code's overdue for some real locking.
>
> Thanks,
>
> - Chris.
> --
> Chris Ball   <cjb@xxxxxxxxxx>
> One Laptop Per Child
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