Subject: Re: get_controlfile() can leak fds in the backend
To: Michael Paquier <michael@paquier.xyz>
Cc: Postgres hackers <pgsql-hackers@lists.postgresql.org>
References: <20190227074728.GA15710@paquier.xyz>
 <748d7697-a25f-029d-e607-dbe4546a1b38@joeconway.com>
 <22d70be7-9334-bfdc-a071-2efca3c52b98@joeconway.com>
 <20190228005445.GC1617@paquier.xyz>
 <d019854e-6325-5b90-9962-4700d92cedf1@joeconway.com>
 <20190228122059.GA11351@paquier.xyz>
From: Joe Conway <mail@joeconway.com>
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Message-ID: <c49b69ec-e2f7-ff33-4f17-0eaa4f2cef27@joeconway.com>
Date: Thu, 28 Feb 2019 16:09:32 -0500
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In-Reply-To: <20190228122059.GA11351@paquier.xyz>
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Content-Type: multipart/mixed; boundary="dw6md1CWuEpLxUgNxaaK0rP0nB1tC4CMY";
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From: Joe Conway <mail@joeconway.com>
To: Michael Paquier <michael@paquier.xyz>
Cc: Postgres hackers <pgsql-hackers@lists.postgresql.org>
Message-ID: <c49b69ec-e2f7-ff33-4f17-0eaa4f2cef27@joeconway.com>
Subject: Re: get_controlfile() can leak fds in the backend
References: <20190227074728.GA15710@paquier.xyz>
 <748d7697-a25f-029d-e607-dbe4546a1b38@joeconway.com>
 <22d70be7-9334-bfdc-a071-2efca3c52b98@joeconway.com>
 <20190228005445.GC1617@paquier.xyz>
 <d019854e-6325-5b90-9962-4700d92cedf1@joeconway.com>
 <20190228122059.GA11351@paquier.xyz>
In-Reply-To: <20190228122059.GA11351@paquier.xyz>

--dw6md1CWuEpLxUgNxaaK0rP0nB1tC4CMY
Content-Type: text/plain; charset=utf-8
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On 2/28/19 7:20 AM, Michael Paquier wrote:
> On Thu, Feb 28, 2019 at 07:11:04AM -0500, Joe Conway wrote:
>> Sure, will do. What are your thoughts on backpatching? This seems
>> unlikely to be a practical concern in the field, so my inclination is =
a
>> master only fix.
>=20
> I agree that this would unlikely become an issue as an error on the
> control file would most likely be a PANIC when updating it, so fixing
> only HEAD sounds fine to me.  Thanks for asking!


Committed and push that way.

By the way, while looking at this, I noted at least a couple of places
where OpenTransientFile() is being passed O_RDWR when the usage is
pretty clearly intended to be read-only. For example at least two
instances in slru.c -- SlruPhysicalReadPage() and
SimpleLruDoesPhysicalPageExist(). Is it worth while searching for and
fixing those instances?

Joe

--=20
Crunchy Data - http://crunchydata.com
PostgreSQL Support for Secure Enterprises
Consulting, Training, & Open Source Development


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