Horton

Re: Avoid possible overflow (src/port/bsearch_arg.c)

Ranier Vilela <ranier.vf@gmail.com>

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From: Ranier Vilela <ranier.vf@gmail.com>
To: Nathan Bossart <nathandbossart@gmail.com>
Cc: Pg Hackers <pgsql-hackers@postgresql.org>
Date: 2024-10-09T16:16:31Z
Lists: pgsql-hackers 
Em ter., 8 de out. de 2024 às 18:28, Nathan Bossart <
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.

best regards,
Ranier Vilela

Commits

  1. Fix overflow in bsearch_arg() with more than INT_MAX elements

  2. Fix typos and grammar in comments and docs

  3. Move bsearch_arg to src/port