>
> On Tue, Mar 23, 2010 at 10:29 AM, Xiaotian Feng <xtfeng@gmail.com> wrote:
>> On Tue, Mar 23, 2010 at 9:34 AM, wzt wzt <wzt.wzt@gmail.com> wrote:
>>>> I can see that the size might cause an overflow in the addition with
>>>> sizeof(struct ipt_get_entries)
>>> That's the integer overflow i pointed.
>>> get.size is copy from the user space, it can be set as 0x7fffffff,
>>> addition with sizeof(struct ipt_get_entries) can be overflow.
>>
>> Patrick's point is that you're using "if (get.size >= INT_MAX /
>> sizeof(struct ipt_get_entries))"
>> So, did you find any chance that get.size * sizeof(struct
>> ipt_get_entries) >= INT_MAX ?
>>
>> And, for the addition overflow, can it be caught by
>>
>> "if (*len != sizeof(struct ipt_get_entries) + get.size)" ???
>>
>>>
>>> if (*len != sizeof(struct ipt_get_entries) + get.size) {
>>> duprintf("get_entries: %u != %zu\n",
>>> *len, sizeof(get) + get.size);
>>> return -EINVAL;
>>> }
>>>
>>> so, check get.size max value before addition with sizeof(struct
>>> ipt_get_entries) to prevent the integer overflow.
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>>
>
