On 10/28/24 13:13, Heikki Linnakangas wrote:
> On 09/10/2024 19:16, Ranier Vilela wrote:
>> Em ter., 8 de out. de 2024 às 18:28, Nathan Bossart
>> <nathandbossart@gmail.com <mailto:nathandbossart@gmail.com>> escreveu:
>>
>> On Tue, Oct 08, 2024 at 04:09:00PM -0300, Ranier Vilela wrote:
>> > The port function *bsearch_arg* mimics the C function
>> > *bsearch*.
>> >
>> > The API signature is:
>> > void *
>> > bsearch_arg(const void *key, const void *base0,
>> > size_t nmemb, size_t size,
>> > int (*compar) (const void *, const void *, void *),
>> > void *arg)
>> >
>> > So, the parameter *nmemb* is size_t.
>> > Therefore, a call with nmemb greater than INT_MAX is possible.
>> >
>> > Internally the code uses the *int* type to iterate through the
>> number of
>> > members, which makes overflow possible.
>>
>> I traced this back to commit bfa2cee (v14), which both moved
>> bsearch_arg()
>> to its current location and adjusted the style a bit. Your patch
>> looks
>> reasonable to me.
>>
>> Thanks for looking.
>
> Committed, thanks.
>
> Based on the original discussion on bfa2cee, I couldn't figure out where
> exactly this new bsearch implementation originated from, but googling
> around, probably *BSD or libiberty. Tomas, do you remember? Not that it
> matters, but I'm curious.
>
I don't remember, unfortunately :-( I think it was one of the *BSDs,
because of license, but I'm not quite sure why I changed the code at all
during the move.
> Some of those other implementations have fixed this, others have not.
> And they all seem to also have the "involes" typo in the comment that we
> fixed in commit 7ef8b52cf07 :-). Ranier, you might want to submit this
> fix to those other projects too.
>
Thanks for fixing this, although I wonder if we can actually hit this,
as we don't really allocate more than 1GB in most places. But it's
possible, and the pre-bfa2cee code handled it fine.
regards
--
Tomas Vondra
