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 4AB2B385840A; Mon, 27 Sep 2021 13:18:55 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 4AB2B385840A
From: "adhemerval.zanella at linaro dot org"
 <sourceware-bugzilla@sourceware.org>
To: glibc-bugs@sourceware.org
Subject: [Bug libc/28377] closefrom_fallback fails when /proc/self/fd is not
 present, which causes unexpected behavior with openssh
Date: Mon, 27 Sep 2021 13:18:55 +0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: changed
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: glibc
X-Bugzilla-Component: libc
X-Bugzilla-Version: 2.34
X-Bugzilla-Keywords: 
X-Bugzilla-Severity: minor
X-Bugzilla-Who: adhemerval.zanella at linaro dot org
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: cc
Message-ID: <bug-28377-131-4TulHFgbvg@http.sourceware.org/bugzilla/>
In-Reply-To: <bug-28377-131@http.sourceware.org/bugzilla/>
References: <bug-28377-131@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: Mon, 27 Sep 2021 13:18:55 -0000

https://sourceware.org/bugzilla/show_bug.cgi?id=3D28377

Adhemerval Zanella <adhemerval.zanella at linaro dot org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |adhemerval.zanella at lina=
ro dot o
                   |                            |rg

--- Comment #2 from Adhemerval Zanella <adhemerval.zanella at linaro dot or=
g> ---
As Florian has state in the https://bugzilla.mindrot.org/show_bug.cgi?id=3D=
3349,
there is not much we can do make it work reliable on Linux. The RLIMIT_NOFI=
LE
fallback some implementations (such the one used on openssh at
openbsd-compat/bsd-closefrom.c) is not possible because it does not really
describe the descriptor range, and iterating over all possible file descrip=
tors
values (INT_MAX) is prohibitively performance-wise. It might work on openssh
since it controls when and how it uses RLIMIT_NOFILE, but it not an option =
for
glibc.

So I think it is a fair assumption that if you want to support closefrom() =
on a
kernel without the syscall suppport, you need to provide the another feasib=
le
kernel interface to allows it (procfs).

Another option is to either abort if /proc can not be opened or remove the
fallback (and abort() as well).

In any case, I am inclined to close this bug.

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