Thread

Re: Small bugs regarding resowner handling in aio.c, catcache.c

Heikki Linnakangas <hlinnaka@iki.fi> — 2025-12-10T09:51:35Z

On 10/12/2025 01:33, Matthias van de Meent wrote:
> Hi Heikki, Andres,
> 
> Whilst looking through catcache.c's code I noticed this piece of code:
> 
> ReleaseCatCacheListWithOwner(CatCList *list, ResourceOwner resowner)
> {
>      [...]
>      if (resowner)
>          ResourceOwnerForgetCatCacheRef(CurrentResourceOwner, &ct->tuple);
> 
> Note how the resowner argument is ignored in favour of
> CurrentResourceOwner; and that probably wasn't what the author
> intended.
> 
> So I looked around a bit, and found 2 more similar instances: one more
> in catcache.c, and one in aio.c.  I can't guarantee that there are no
> other comparable issues, but at least I could not immediately find any
> functions that ignore their ResourceOwner argument in favour of
> CurrentResourceOwner.
> 
> The issue in aio.c is externally visible, so it might trigger issues.
> However, every caller in the tree uses CurrentResourceOwner, so only
> extensions could trigger this bug.
> The two issues in catcache.c are benign: No external code can trigger
> it with a different resource owner; and while no internal code would
> trigger it either, it's better to use the provided resowner, so that
> future callers won't activate the bug.
> 
> Attached a fix for all 3 cases.

Pushed and backpatched, thanks!

- Heikki