Re: NULL pointer dereference in sysfs_readdir

[Michael Buesch]

On Sunday 22 October 2006 11:08, Stefan Richter wrote:
> > Yeah, I found that offset, too, but:
> > 
> > There is only one usage of s_dentry
> > if (next->s_dentry)
> > 
> > But _before_ that there already comes
> > if (!next->s_element)
> > 
> > So, if "next" was NULL, it would already oops there.
> 
> What if "next" became NULL afterwards?

Hm, yeah. Makes kind of sense.

> I know it's unlikely (but so is 
> the whole bug, given that we have just one reporter despite the bug's
> age), but is it impossible? IOW does sysfs_readdir have any indirect
> mutex protection?

I think it's protected by the BKL, but I dunno if that's sufficient here.

-- 
Greetings Michael.
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