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From: Richard Weinberger <richard.weinberger@gmail.com>
To: Samuel Dionne-Riel <samuel@dionne-riel.com>
Cc: LKML <linux-kernel@vger.kernel.org>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	graham@grahamc.com, Oleg Nesterov <oleg@redhat.com>,
	Kees Cook <keescook@chromium.org>,
	mhocko@suse.com, Andrew Morton <akpm@linux-foundation.org>
Subject: Re: Userspace regression in LTS and stable kernels
Date: Thu, 14 Feb 2019 00:36:29 +0100	[thread overview]
Message-ID: <CAFLxGvwpuxKF4UWdsULwQWo7kgVLMNHC=77dN+w-A0a6avrAXA@mail.gmail.com> (raw)
In-Reply-To: <CAN1fySViLgrLAHHfTHMef-Bkh73kUHKP-ava6TbgALeSE4LfFw@mail.gmail.com>

[CC'in relevant folks]

On Thu, Feb 14, 2019 at 12:19 AM Samuel Dionne-Riel
<samuel@dionne-riel.com> wrote:
>
> Hi,
>
> I am posting as a representative of the NixOS Linux distribution,
> about a userspace regression on 5.0-rc* which recently was backported
> to the 4.14.99, 4.19.21 and 4.20.8 current LTS and stable versions.
> The issue has been reported to the bug tracker, bug 202497, but seems
> to have gone unnoticed by the maintainers.
>
> The issue seems to break userspace for long-standing patterns in the
> NixOS distribution, with regards to use of the shebangs.
>
> Here is an example shebang causing an issue:
>
> #! /nix/store/mbwav8kz8b3y471wjsybgzw84mrh4js9-perl-5.28.1/bin/perl
> -I/nix/store/x6yyav38jgr924nkna62q3pkp0dgmzlx-perl5.28.1-File-Slurp-9999.25/lib/perl5/site_perl
> -I/nix/store/ha8v67sl8dac92r9z07vzr4gv1y9nwqz-perl5.28.1-Net-DBus-1.1.0/lib/perl5/site_perl
> -I/nix/store/dcrkvnjmwh69ljsvpbdjjdnqgwx90a9d-perl5.28.1-XML-Parser-2.44/lib/perl5/site_perl
> -I/nix/store/rmji88k2zz7h4zg97385bygcydrf2q8h-perl5.28.1-XML-Twig-3.52/lib/perl5/site_perl

This this ever work correctly? It is longer than BINPRM_BUF_SIZE.

> (The shebang was artificially wrapped spaces replaced by newlines)
>
> Another contributor tracked the regression it to commit
> 8099b047ecc431518b9bb6bdbba3549bbecdc343 in the 5.0-rc* tree.
>
> I bring no particular fix to the issue, but I believe it should at
> least be fast-tracked to a revert for the stable and LTS branches, and
> since 5.0 might drop soon, a solution worked on, or possibly a revert
> until one is figured out.

Your shebang line exceeds BINPRM_BUF_SIZE.
Before the said commit the kernel silently truncated the shebang line
(and corrupted it),
now it tells the user that the line is too long.

Thanks,
//richard

  parent reply	other threads:[~2019-02-13 23:36 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-02-13 17:57 Userspace regression in LTS and stable kernels Samuel Dionne-Riel
2019-02-13 18:00 ` Samuel Dionne-Riel
2019-02-13 23:36 ` Richard Weinberger [this message]
2019-02-14  0:41   ` Samuel Dionne-Riel
2019-02-14  0:54     ` Kees Cook
2019-02-14  1:27       ` Samuel Dionne-Riel
2019-02-14  1:35         ` Kees Cook
2019-02-14  3:16           ` Samuel Dionne-Riel
2019-02-14  0:41   ` Kees Cook
2019-02-14 17:56   ` Linus Torvalds
2019-02-14 20:20     ` Andrew Morton
2019-02-15  7:00       ` Greg Kroah-Hartman
2019-02-15  7:13         ` Greg Kroah-Hartman
2019-02-15  9:10         ` Michal Hocko
2019-02-15  9:20           ` Greg Kroah-Hartman
2019-02-15  9:42             ` Michal Hocko
2019-02-15 15:19               ` Sasha Levin
2019-02-15 15:52                 ` Michal Hocko
2019-02-15 16:18                   ` Samuel Dionne-Riel
2019-02-15 18:02                     ` Sasha Levin
2019-02-15 18:00                   ` Sasha Levin
2019-02-18 12:56                     ` Michal Hocko

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