From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <sourceware-bugzilla@sourceware.org>
Received: by sourceware.org (Postfix, from userid 48)
 id 623FD398D043; Wed, 10 Feb 2021 08:19:18 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 623FD398D043
From: "sjon at hortensius dot net" <sourceware-bugzilla@sourceware.org>
To: glibc-bugs@sourceware.org
Subject: [Bug network/27389] New: getaddrinfo in chroot broken by added
 dlopen block
Date: Wed, 10 Feb 2021 08:19:18 +0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: new
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: glibc
X-Bugzilla-Component: network
X-Bugzilla-Version: 2.33
X-Bugzilla-Keywords: 
X-Bugzilla-Severity: normal
X-Bugzilla-Who: sjon at hortensius dot net
X-Bugzilla-Status: UNCONFIRMED
X-Bugzilla-Resolution: 
X-Bugzilla-Priority: P2
X-Bugzilla-Assigned-To: unassigned at sourceware dot org
X-Bugzilla-Target-Milestone: ---
X-Bugzilla-Flags: 
X-Bugzilla-Changed-Fields: bug_id short_desc product version bug_status
 bug_severity priority component assigned_to reporter target_milestone
Message-ID: <bug-27389-131@http.sourceware.org/bugzilla/>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
X-Bugzilla-URL: http://sourceware.org/bugzilla/
Auto-Submitted: auto-generated
MIME-Version: 1.0
X-BeenThere: glibc-bugs@sourceware.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: Glibc-bugs mailing list <glibc-bugs.sourceware.org>
List-Unsubscribe: <https://sourceware.org/mailman/options/glibc-bugs>,
 <mailto:glibc-bugs-request@sourceware.org?subject=unsubscribe>
List-Archive: <https://sourceware.org/pipermail/glibc-bugs/>
List-Help: <mailto:glibc-bugs-request@sourceware.org?subject=help>
List-Subscribe: <https://sourceware.org/mailman/listinfo/glibc-bugs>,
 <mailto:glibc-bugs-request@sourceware.org?subject=subscribe>
X-List-Received-Date: Wed, 10 Feb 2021 08:19:18 -0000

https://sourceware.org/bugzilla/show_bug.cgi?id=3D27389

            Bug ID: 27389
           Summary: getaddrinfo in chroot broken by added dlopen block
           Product: glibc
           Version: 2.33
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: network
          Assignee: unassigned at sourceware dot org
          Reporter: sjon at hortensius dot net
  Target Milestone: ---

I have an issue that I suspect is caused by a recent glibc change, but I
haven't 100% ruled out another cause, so this report might be bogus.

I use PHP-FPM [1] with chroots enabled. Since upgrading glibc, name resolvi=
ng
(via DNS) fails with "getaddrinfo failed: System error" in my chroot and I'm
pretty sure it is caused by the recently added "Block attempts to dlopen any
module we haven't already opened" [2]

What seems to happen is that the PHP-FPM master process only loads
libnss_files.so.2 and libnss_systemd.so.2 because it uses that to resolve t=
he
username (it matches nsswitch which contains: "passwd: files systemd")

If any of the FPM workers then attempts to perform dns resolving, that fails
because libnss_dns.so.2 has not been loaded yet (even though I made it
available in the chroot), and due to the recent change, it won't be loaded
either.

I have confirmed I can "fix" it by forcing the fpm master to load the dns
module by modifying nsswitch.conf outside of the chroot to contains "passwd:
dns files systemd", this fixes it

1. https://www.php.net/manual/en/install.fpm.php
2.
https://github.com/bminor/glibc/commit/429029a73ec2dba7f808f69ec8b9e3d84e13=
e804#diff-9305f1992144bc8c923a840d44827642f1c3f57e3df85a69357fff2fe7370fb8R=
352

--=20
You are receiving this mail because:
You are on the CC list for the bug.=