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

[Cody P Schafer <cody@linux.vnet.ibm.com>]

>> +	/* 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