Re: [PATCH v3 0/4] Add overflow checks for several syscalls

[David Hildenbrand]

On 28.01.23 07:32, Wupeng Ma wrote:
> From: Ma Wupeng <mawupeng1@xxxxxxxxxx>
>
> While testing mlock, we have a problem if the len of mlock is ULONG_MAX.
> The return value of mlock is zero. But nothing will be locked since the
> len in do_mlock overflows to zero due to the following code in mlock:
>
>    len = PAGE_ALIGN(len + (offset_in_page(start)));
>
> The same problem happens in munlock.
>
> Add new check and return -EINVAL to fix this overflowing scenarios since
> they are absolutely wrong.
>
> Similar logic is used to fix problems with multiple syscalls.
>
> Changelog since v2[2]:
> - modified the way of checking overflows based on Andrew's comments
>
> Changelog since v1[1]:
> - only check overflow rather than access_ok to keep backward-compatibility

Do you have some test cases and could we add them to LTP, for example?

--
Thanks,

David / dhildenb