Re: Fix possible bogus array out of bonds (src/backend/access/brin/brin_minmax_multi.c) - Mailing list pgsql-hackers

From Ranier Vilela
Subject Re: Fix possible bogus array out of bonds (src/backend/access/brin/brin_minmax_multi.c)
Date
Msg-id CAEudQAqZDPprSYyVdWWWT8yxz_TE47npp0RpY4eARsVrC=QFQA@mail.gmail.com
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In response to Re: Fix possible bogus array out of bonds (src/backend/access/brin/brin_minmax_multi.c)  (Kyotaro Horiguchi <horikyota.ntt@gmail.com>)
List pgsql-hackers
Em dom., 28 de ago. de 2022 às 22:06, Kyotaro Horiguchi <horikyota.ntt@gmail.com> escreveu:
At Fri, 26 Aug 2022 10:28:50 -0300, Ranier Vilela <ranier.vf@gmail.com> wrote in
> At function has_matching_range, if variable ranges->nranges == 0,
> we exit quickly with a result equal to false.
>
> This means that nranges can be zero.
> It occurs then that it is possible then to occur an array out of bonds, in
> the initialization of the variable maxvalue.
> So if nranges is equal to zero, there is no need to initialize minvalue and
> maxvalue.
>
> The patch tries to fix it, avoiding possible errors by using maxvalue.

However it seems that nranges will never be zero, still the fix looks
good to me since it is generally allowed to be zero. I don't find a
similar mistake related to Range.nranges.
Thanks  Kyotaro for taking a look at this.

regards,
Ranier Vilela

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