Horton

Thread

Commits

  1. Fix possible future cache reference leak in ALTER EXTENSION ADD/DROP.

  1. Possible cache reference leak by removeExtObjInitPriv

    Kyotaro Horiguchi <horikyota.ntt@gmail.com> — 2020-04-17T06:18:31Z

    Hello.

Recently a cache reference leak was reported then fixed [1].

I happened to notice a similar possible leakage in
removeEtObjInitPriv. I haven't found a way to reach the code, but can
be forcibly caused by tweaking the condition.

Please find the attached.

regards.

[1] https://www.postgresql.org/message-id/BYAPR08MB5606D1453D7F50E2AF4D2FD29AD80@BYAPR08MB5606.namprd08.prod.outlook.com

  2. Re: Possible cache reference leak by removeExtObjInitPriv

    Tom Lane <tgl@sss.pgh.pa.us> — 2020-04-17T17:07:15Z

    Kyotaro Horiguchi <horikyota.ntt@gmail.com> writes:
> Recently a cache reference leak was reported then fixed [1].
> I happened to notice a similar possible leakage in
> removeEtObjInitPriv. I haven't found a way to reach the code, but can
> be forcibly caused by tweaking the condition.
> Please find the attached.

Ugh.  recordExtObjInitPriv has the same problem.

I wonder whether there is any way to teach Coverity, or some other
static analyzer, to look for code paths that leak cache refcounts.
It seems isomorphic to detecting memory leaks, which Coverity is
reasonably good at.

			regards, tom lane

  3. Re: Possible cache reference leak by removeExtObjInitPriv

    Kyotaro Horiguchi <horikyota.ntt@gmail.com> — 2020-04-20T08:28:29Z

    At Fri, 17 Apr 2020 13:07:15 -0400, Tom Lane <tgl@sss.pgh.pa.us> wrote in 
> Kyotaro Horiguchi <horikyota.ntt@gmail.com> writes:
> > Recently a cache reference leak was reported then fixed [1].
> > I happened to notice a similar possible leakage in
> > removeEtObjInitPriv. I haven't found a way to reach the code, but can
> > be forcibly caused by tweaking the condition.
> > Please find the attached.
> 
> Ugh.  recordExtObjInitPriv has the same problem.

Thanks for commit it.

> I wonder whether there is any way to teach Coverity, or some other
> static analyzer, to look for code paths that leak cache refcounts.
> It seems isomorphic to detecting memory leaks, which Coverity is
> reasonably good at.

Indeed.

regards.

-- 
Kyotaro Horiguchi
NTT Open Source Software Center