Re: [PATCH v5 3.1.0-rc4-tip 1/26] uprobes: Auxillary routines toinsert, find, delete uprobes

[Srikar Dronamraju]

* Peter Zijlstra <peterz@xxxxxxxxxxxxx> [2011-09-26 13:18:38]:

> On Tue, 2011-09-20 at 16:42 +0100, Stefan Hajnoczi wrote:
> > On Tue, Sep 20, 2011 at 05:29:49PM +0530, Srikar Dronamraju wrote:
> > > +static void delete_uprobe(struct uprobe *uprobe)
> > > +{
> > > +	unsigned long flags;
> > > +
> > > +	spin_lock_irqsave(&uprobes_treelock, flags);
> > > +	rb_erase(&uprobe->rb_node, &uprobes_tree);
> > > +	spin_unlock_irqrestore(&uprobes_treelock, flags);
> > > +	put_uprobe(uprobe);
> > > +	iput(uprobe->inode);
> > 
> > Use-after-free when put_uprobe() kfrees() the uprobe?
> 
> I suspect the caller still has one, and this was the reference for being
> part of the tree. But yes, that could do with a comment.
> 

Yes, the caller has a reference, However I went ahead and changed the
order of the last two statements.

> The comment near atomic_set() in __insert_uprobe() isn't too clear
> either. /* get access + drop ref */, would naively seem +1 -1 = 0,
> instead of +1 +1 = 2.
> 

Okay, Have modified the comment to /* get access + creation ref */

-- 
Thanks and Regards
Srikar
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