Horton

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: Pg Hackers <pgsql-hackers@postgresql.org>
Date: 2024-10-08T19:09:00Z
Lists: pgsql-hackers

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Hi.

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.

Trivial fix attached.

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