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From: Florian Weimer <fw@deneb.enyo.de>
To: Paul Eggert <eggert@cs.ucla.edu>
Cc: bug-gnulib@gnu.org, Kamil Dudka <kdudka@redhat.com>
Subject: Re: [PATCH] fchmodat, lchmod: port to buggy Linux filesystems
Date: Wed, 11 Mar 2020 09:45:07 +0100	[thread overview]
Message-ID: <87y2s7xoto.fsf@mid.deneb.enyo.de> (raw)
In-Reply-To: <bdced4c8-bcef-70c7-4382-b0eb6d1c7615@cs.ucla.edu> (Paul Eggert's message of "Wed, 11 Mar 2020 01:03:57 -0700")

* Paul Eggert:

> On 3/10/20 12:30 PM, Florian Weimer wrote:
>> The glibc implementation needs /proc to avoid the race.  There is no
>> way around that, otherwise we introduce a security vulnerability.
>
> It is unfortunate that we have dueling paranoia here. coreutils mknod is 
> paranoid so it uses lchmod to avoid a race, and then glibc lchmod is paranoid so 
> it refuses to work with lchmod unless /proc is mounted.

I now wonder if neither gnulib nor glibc should pretend that they can
implement lchmod and fchmodat on Linux in a usable fashion.

I added the emulation to glibc mostly because it was in gnulib.
Otherwise, I would have insisted that a proper system call be
implemented first.


  reply	other threads:[~2020-03-11  8:46 UTC|newest]

Thread overview: 31+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-13 18:42 [PATCH] fchmodat, lchmod: port to buggy Linux filesystems Paul Eggert
2020-02-14  3:29 ` Bruno Haible
2020-02-16 17:24   ` Bruno Haible
2020-02-16 18:31     ` Paul Eggert
2020-02-16 18:58       ` Bruno Haible
2020-02-14  3:46 ` Bruno Haible
2020-02-14 21:02   ` Paul Eggert
2020-02-16 21:38     ` Bruno Haible
2020-02-16 22:28       ` Bruno Haible
2020-02-22 23:46       ` Bruno Haible
2020-02-23  8:15         ` Paul Eggert
2020-02-23 10:58           ` Bruno Haible
2020-02-23 23:56             ` Paul Eggert
2020-02-24  2:27               ` overriding glibc stub functions Bruno Haible
2020-02-24  7:44                 ` Paul Eggert
2020-02-23  1:35 ` [PATCH] fchmodat, lchmod: port to buggy Linux filesystems Bruno Haible
2020-02-23  7:22   ` Paul Eggert
2020-03-09 17:30 ` Pádraig Brady
2020-03-09 18:51   ` Paul Eggert
2020-03-09 23:45     ` Pádraig Brady
2020-03-10 11:52       ` Florian Weimer
2020-03-10 15:09         ` Kamil Dudka
2020-03-10 19:27         ` Pádraig Brady
2020-03-10 19:30           ` Florian Weimer
2020-03-11  8:03             ` Paul Eggert
2020-03-11  8:45               ` Florian Weimer [this message]
2020-03-11 16:04                 ` Paul Eggert
2020-03-11  8:25             ` Paul Eggert
2020-03-11  8:40               ` Florian Weimer
2020-03-11  9:04             ` Kamil Dudka
2020-03-11 16:36               ` Paul Eggert

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