From: Florian Weimer <fweimer@redhat.com>
To: Carlos O'Donell <carlos@redhat.com>,
GNU C Library <libc-alpha@sourceware.org>,
Andreas Schwab <schwab@suse.de>,
"Dmitry V. Levin" <ldv@altlinux.org>
Subject: Re: [PATCH v4] Improve DST handling (Bug 23102, Bug 21942, Bug 18018, Bug, 23259, CVE-2011-0536 ).
Date: Mon, 11 Jun 2018 07:28:00 -0000 [thread overview]
Message-ID: <2ca2dfa9-2066-9cfb-9851-6dc8415b1085@redhat.com> (raw)
In-Reply-To: <a98a01e8-7358-b848-6778-5bdf21d633be@redhat.com>
On 06/11/2018 04:54 AM, Carlos O'Donell wrote:
>>> I consider the following valid:
>>>
>>> [$ORIGIN/../$LIB]
>> I'm actually asking about this:
>>
>> [$LIB:$ORIGIN/../$LIB]
>>
>> Doesn't the current code reject this?
> The current code does not reject this. In fact it accepts $LIB in RPATH
> et. al. because there is no code to reject it. Only $ORIGIN has any
> restrictions.
I meant the $ORIGN part. As far as I understand it, start will not be
close to input for the second part containing origin (after the :), so
this check in _dl_dst_substitute should reject it:
|| (input != start + 1
|| (input > start + 2 && input[-2] != ':'))))
I'm not sure that this is right.
> Should all paths get tested for trusted paths for a SUID/SGID binary?
> It seems like that's the right idea.
>
> @@ -365,7 +383,8 @@ _dl_dst_substitute (struct link_map *l, const char *start,
>
> /* In SUID/SGID programs, after DST expansion the normalized
> path must be rooted in one of the trusted directories. */
> - if (__glibc_unlikely (check_for_trusted)
> + if (__glibc_unlikely (__libc_enable_secure)
> + && l->l_type == lt_executable
> && !is_trusted_path_normalize (result, wp - result))
> {
> *result = '\0';
>
> Just drop check_for_trusted, and execute the is_trusted_path_normalize
> check for all SUID/SGID paths?
No, $ORIGIN in a trusted path is itself trusted (because you cannot
manipulate it using hard links). I think there are installations out
there which depend on this.
Thanks,
Florian
next prev parent reply other threads:[~2018-06-11 7:28 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-06-06 5:03 [PATCH] " Carlos O'Donell
2018-06-06 14:01 ` Florian Weimer
2018-06-06 14:55 ` Carlos O'Donell
2018-06-06 14:17 ` Florian Weimer
2018-06-06 15:59 ` Carlos O'Donell
2018-06-06 15:47 ` Andreas Schwab
2018-06-06 16:01 ` Carlos O'Donell
2018-06-06 16:10 ` Carlos O'Donell
2018-06-06 16:31 ` Andreas Schwab
2018-06-06 17:10 ` Carlos O'Donell
2018-06-06 17:28 ` Florian Weimer
2018-06-06 18:49 ` Carlos O'Donell
2018-06-06 18:56 ` Florian Weimer
2018-06-06 20:04 ` Carlos O'Donell
2018-06-07 6:49 ` Andreas Schwab
2018-06-08 2:08 ` Carlos O'Donell
2018-06-11 8:04 ` Andreas Schwab
2018-06-12 3:08 ` Carlos O'Donell
2018-06-12 7:31 ` Andreas Schwab
2018-06-12 12:46 ` Carlos O'Donell
2018-06-12 13:02 ` Andreas Schwab
2018-06-12 13:03 ` Carlos O'Donell
2018-06-06 20:19 ` Carlos O'Donell
2018-06-07 11:38 ` Florian Weimer
2018-06-08 2:14 ` Carlos O'Donell
2018-06-07 12:16 ` Florian Weimer
2018-06-08 4:15 ` Carlos O'Donell
2018-06-08 5:21 ` Florian Weimer
2018-06-08 5:46 ` Carlos O'Donell
2018-06-08 5:50 ` Carlos O'Donell
2018-06-07 12:43 ` Florian Weimer
2018-06-08 5:37 ` Carlos O'Donell
2018-06-08 5:45 ` [PATCH v4] " Carlos O'Donell
2018-06-08 5:51 ` Florian Weimer
2018-06-08 6:03 ` Carlos O'Donell
2018-06-08 6:25 ` Florian Weimer
2018-06-11 2:55 ` Carlos O'Donell
2018-06-11 7:28 ` Florian Weimer [this message]
2018-06-11 14:44 ` Carlos O'Donell
2018-06-12 3:46 ` Carlos O'Donell
2018-06-12 13:08 ` [PATCH v6] " Carlos O'Donell
2018-06-12 13:20 ` Andreas Schwab
2018-06-12 13:23 ` Andreas Schwab
2018-06-12 14:10 ` Carlos O'Donell
2018-06-12 14:34 ` Andreas Schwab
2018-06-12 14:31 ` Florian Weimer
2018-06-12 14:36 ` Carlos O'Donell
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