From: Adhemerval Zanella <adhemerval.zanella@linaro.org>
To: Florian Weimer <fw@deneb.enyo.de>,
Adhemerval Zanella via Libc-alpha <libc-alpha@sourceware.org>
Subject: Re: [PATCH v2] Ensure standard file descriptors are open on start
Date: Wed, 19 Aug 2020 16:25:35 -0300 [thread overview]
Message-ID: <71aa6d5c-bc1c-147c-19c2-e736411d3a47@linaro.org> (raw)
In-Reply-To: <874koycuv5.fsf@mid.deneb.enyo.de>
On 19/08/2020 16:13, Florian Weimer wrote:
> * Adhemerval Zanella via Libc-alpha:
>
>> But is it really a useful hardening, even for SUID binaries? The
>> check_one_fd only check if the file descriptor is opened and redirects
>> it to /dev/full otherwise. It does really 'protect' if a constructor
>> or a LD_PRELOAD redirects the STD*_FILENO to something else.
>
> The protection is against messages intended for standard input and
> standard error showing up in explicitly open files (which would
> otherwise receive descriptors 3 and higher). This is not too
> far-fetched, given that such messages could well have parts that are
> under control of a different user.
>
Yes, but in which scenario this is really a vector of attack? One could
still open/close/dup to redirect the messages.
next prev parent reply other threads:[~2020-08-19 19:25 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-19 12:41 Arsen Arsenović
2020-08-19 16:28 ` Joseph Myers
2020-08-19 17:46 ` Zack Weinberg
2020-08-19 17:50 ` Joseph Myers
2020-08-19 18:20 ` Adhemerval Zanella
2020-08-19 19:13 ` Florian Weimer
2020-08-19 19:25 ` Adhemerval Zanella [this message]
2020-08-19 19:27 ` Florian Weimer
2020-08-19 19:35 ` Adhemerval Zanella
2020-08-19 19:40 ` Arsen Arsenović
2020-08-19 21:04 ` Michael Morrell
2020-08-19 22:32 ` Joseph Myers
2020-08-19 23:45 ` Arsen Arsenović
2020-08-20 22:00 ` Paul Eggert
2020-08-20 23:25 ` Arsen Arsenović
2020-08-27 15:56 ` Zack Weinberg
2020-08-27 18:21 ` Paul Eggert
2020-08-28 0:12 ` Arsen Arsenović
2020-09-04 17:49 ` Arsen Arsenović
2020-09-11 7:47 ` ping^2 " Arsen Arsenović
2020-08-19 23:16 ` Rich Felker
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