[lustre-devel] [bug report] staging: add Lustre file system client support

[Greg KH <gregkh@linuxfoundation.org>]

On Tue, Dec 06, 2016 at 02:10:13PM -0500, Oleg Drokin wrote:
> 
> On Dec 6, 2016, at 1:37 PM, Dan Carpenter wrote:
> 
> > On Tue, Dec 06, 2016 at 10:44:54AM -0500, Oleg Drokin wrote:
> >> I see, indeed, it all makes sense now.
> >> So basically if we unconditionally check for the size to be > 0, we should be
> >> fine then, I imagine.
> >> On the other hand there's probably no se for no param and nonzero param len,
> >> so it's probably even better to enforce size as zero when no param.
> > 
> > Checking for > 0 is not enough, because it could also have an integer
> > overflow on 32 bit systems.  We need to cap the upper bound as well.
> 
> How would it play out, though?
> offsetof(struct lstcon_test, tes_param[large_positive_int]) would result in
> some real "large" negative number.
> So trying to allocate this many negative bytes would fail, right?

Not always.  Please properly bound your allocations.

thanks,

greg k-h