Re: NGROUPS 2.6.2rc2

[Hugh Dickins]

On Tue, 27 Jan 2004, Tim Hockin wrote:
> On Tue, Jan 27, 2004 at 04:46:15PM -0800, Andrew Morton wrote:
> > +
> > +	if (info->ngroups > TASK_SIZE/sizeof(group))
> > +		return -EFAULT;
> > +	if (!access_ok(VERIFY_WRITE, grouplist, info->ngroups * sizeof(group)))
> > +		return -EFAULT;
> > 
> > Why are many functions playing with TASK_SIZE?
> 
> Not sure - I thought it was maybe a paranoid check, Rusty included it in his
> version of a similar patch a while ago.

Yes, a necessary paranoid check: without it, info->ngroups * sizeof(group)
can easily wrap to something small, and access_ok pass when it should fail.

Hugh

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