Re: [PATCH] perf: prevent overflow in size calculation

[Cody P Schafer]

> > +	/* Check for overflow when calculating sizeof_sym_hist */
> > +	if (size > (SIZE_MAX / sizeof(u64)))
> > +		return -1;
>
> How does it guarantee that the end result which used in zalloc below
> would not overflow?
>
> > +
> > +	sizeof_sym_hist = (sizeof(struct sym_hist) + size * sizeof(u64));
> >   	notes->src = zalloc(sizeof(*notes->src) + symbol_conf.nr_events * sizeof_sym_hist);
> >   	if (notes->src == NULL)
> >   		return -1;

Whoops. Thanks for pointing that out.
I've sent a fixed up patch (the check for sizeof_sym_hist wasn't even 
complete)

--
Cody


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