Devuan bug report logs - #498
libc6: Permission denied, intermittent in execve

Package: libc6; Maintainer for libc6 is (unknown); Source for libc6 is src:glibc.

Reported by: Alessandro Vesely <vesely@tana.it>

Date: Mon, 27 Jul 2020 08:48:01 UTC

Severity: normal

Tags: debian

Merged with 497

Found in version 2.28-10

Forwarded to https://bugs.debian.org/966343

Full log

🔗 View this message in rfc822 format

X-Loop: owner@bugs.devuan.org
Subject: bug#498: Bug#966343: bug#498: libc6: Permission denied, intermittent in execve
Reply-To: Aurelien Jarno <aurelien@aurel32.net>, 498@bugs.devuan.org
Resent-From: Aurelien Jarno <aurelien@aurel32.net>
Resent-To: devuan-bugs@lists.dyne.org
Resent-CC: devuan-dev@lists.dyne.org
X-Loop: owner@bugs.devuan.org
Resent-Date: Tue, 28 Jul 2020 22:33:02 +0000
Resent-Message-ID: <handler.498.B498.15959748016097@bugs.devuan.org>
Resent-Sender: owner@bugs.devuan.org
X-Devuan-PR-Message: followup 498
X-Devuan-PR-Package: libc6
X-Devuan-PR-Keywords: debian
References: <159583832778.5523.4267786497736057480.reportbug@pcale.tana> <4c3f732a-b026-a7a6-bea5-c49fff74267a@tana.it> <20200727091401.GQ3011@hindley.org.uk> <4c3f732a-b026-a7a6-bea5-c49fff74267a@tana.it> <1a948266-b3c2-e3c6-6f91-fda019203850@tana.it> <20200727101344.wovj4a2l4g4xb2hk@function> <20200727101344.wovj4a2l4g4xb2hk@function> <4c3f732a-b026-a7a6-bea5-c49fff74267a@tana.it> <15a0722b-ed58-a804-7d66-12ab5693329e@tana.it> <4c3f732a-b026-a7a6-bea5-c49fff74267a@tana.it>
Received: via spool by 498-submit@bugs.devuan.org id=B498.15959748016097
          (code B ref 498); Tue, 28 Jul 2020 22:33:02 +0000
Received: (at 498) by bugs.devuan.org; 28 Jul 2020 22:20:01 +0000
Delivered-To: devuanbugs@dyne.org
Received: from tupac3.dyne.org [195.169.149.119]
	by doc.devuan.org with IMAP (fetchmail-6.4.0.beta4)
	for <debbugs@localhost> (single-drop); Tue, 28 Jul 2020 22:20:01 +0000 (UTC)
Received: from hall.aurel32.net (hall.aurel32.net [195.154.113.88])
	(using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits))
	(No client certificate requested)
	by vm6.ganeti.dyne.org (Postfix) with ESMTPS id E3FEEF608DA
	for <498@bugs.devuan.org>; Wed, 29 Jul 2020 00:14:59 +0200 (CEST)
Authentication-Results: vm6.ganeti.dyne.org;
	dkim=pass (2048-bit key; secure) header.d=aurel32.net header.i=@aurel32.net header.b="RzTXUsbY";
	dkim-atps=neutral
DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=aurel32.net
	; s=202004.hall; h=In-Reply-To:Content-Type:MIME-Version:References:
	Message-ID:Subject:Cc:To:From:Date:Content-Transfer-Encoding:From:Reply-To:
	Subject:Content-ID:Content-Description:X-Debbugs-Cc;
	bh=7Ksfl4NFsU2PVvrTieylN3C1A8tB6Y4MzI+HHhAGCVM=; b=RzTXUsbYTW6aIA37CKsfnDrhTI
	3wtLyT0rRx6GD+uLIH7Eeh5/ZuVxVEh7eV9sQ7lSpz+EcfB8b5wkiCrGySQ5/yubvJWe7TCMVhp8B
	2PqJxYSJCo+qSBYgfWCF//Jgi46uEXZXFGdIB6RmS+qNhvoIrxiIFqk+o8lwkenne7AUqC3zRJBlG
	wG+ssVBfztaNes5My7P2v5HComNyKkZ65FBuFSLXh2Ygz3NCFRxee4jOcwMd7vEcsKd93v4AOyfWc
	Hd8LfTnfLXNQxOzDo+KyqR1blN1b/DUaJeqMHILqeehVX4C3h6qLd6jUldgCFL28IEMfMk5tuvEtu
	Ee4BeBPg==;
Received: from ohm.aurel32.net ([2001:bc8:30d7:111::1000])
	by hall.aurel32.net with esmtpsa (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256)
	(Exim 4.92)
	(envelope-from <aurelien@aurel32.net>)
	id 1k0Xs9-0003eu-EP; Wed, 29 Jul 2020 00:14:57 +0200
Received: from aurel32 by ohm.aurel32.net with local (Exim 4.94)
	(envelope-from <aurelien@aurel32.net>)
	id 1k0Xs6-0028Fv-Kv; Wed, 29 Jul 2020 00:14:54 +0200
Date: Wed, 29 Jul 2020 00:14:54 +0200
From: Aurelien Jarno <aurelien@aurel32.net>
To: Alessandro Vesely <vesely@tana.it>, 966343-done@bugs.debian.org
Cc: 498@bugs.devuan.org
Message-ID: <20200728221454.GJ8215@aurel32.net>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <15a0722b-ed58-a804-7d66-12ab5693329e@tana.it>
User-Agent: Mutt/1.14.0 (2020-05-02)
X-Spam-Status: No, score=-0.2 required=5.0 tests=DKIM_SIGNED,DKIM_VALID,
	DKIM_VALID_AU,DKIM_VALID_EF,SPF_HELO_PASS autolearn=disabled
	version=3.4.2
X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on tupac3.dyne.org

Hi,

On 2020-07-27 19:01, Alessandro Vesely wrote:
> On Mon, 27 Jul 2020 12:13:44 +0200 Samuel Thibault <sthibault@debian.org> wrote:
> > Alessandro Vesely, le lun. 27 juil. 2020 11:47:34 +0200, a ecrit:
> > > So this turns out to be a documentation bug.  The execve man page should mention that EACCESS can result as an (unforeseen) apparmor impediment.
> > 
> > Well, basically all system calls would then need this...
> 
> 
> Yeah, likely.  How many man pages have snippets like "[...] denied for one of the directories in the path [...]"?
>
> Yet, considering the following examples, they seem to have been written manually rather than resorting to some sort of script:

There are many syscalls that might end up returning EACCESS. Mapping
them to the corresponding libc functions might not be always fully
linear.

[snip]

> Philip Couling commented that the man page /could/ mention security extensions since they are prevelent. See:
> https://unix.stackexchange.com/questions/600174/identical-execve-causes-permission-denied-for-one-program-but-not-another/600529#comment1121270_600529
> 
> For execve, for example, one could add that permissions are not derived from file flags only.  For example:
> 
> OLD:
> 
>        EACCES Execute permission is denied for the file or a script or ELF interpreter.
> 
> NEW:
> 
>        EACCES Execute permission for the file or a script or ELF interpreter is denied either by flags or by security modules.
> 
> 
> Would that be correct?  Do all "DENIED" operations result in EACCES?  And what do other security modules do?  Hmm...  Starting to document that mess from the point of view of programs getting such failure codes would allow better logging and better troubleshooting.

That seems correct for apparmor (although it can also return ENOENT in
case of race condition), not sure about other security modules. seccomp
just kills the process, not sure you want to mention that in every
possible manpages.

In any case this is now out of scope for the glibc package, so I am
closing the bug. If you feel that the doc needs to be updated, please
open a bug against the corresponding package.

Regards,
Aurelien

-- 
Aurelien Jarno                          GPG: 4096R/1DDD8C9B
aurelien@aurel32.net                 http://www.aurel32.net

Send a report that this bug log contains spam.

Devuan bug report logs - #498 libc6: Permission denied, intermittent in execve

Devuan bug report logs - #498
libc6: Permission denied, intermittent in execve