linux-kernel - Re: "core dump helper" runs always as root

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Message-ID: <48807821.8050504@swiss-it.ch>
Date:	Fri, 18 Jul 2008 13:01:53 +0200
From:	Reto Buerki <buerki@...ss-it.ch>
To:	linux-kernel@...r.kernel.org
Subject: Re: "core dump helper" runs always as root

> If we run the usermode helper with the privileges of the dying process, what do 
> we do about rlimit enforcement?  They don't have a PAM environment, so either 
> they get the default rlimits, or we have to make them inherit their limits from 
> the dying process.  This is very problematic if the process died due to 
> exceeding an rlimit.

I'm not sure if I understand your objection correctly, but I thought
RLIMIT_CORE is ignored when using piped syntax with core_pattern.

At least this is how I interpret the code and the corresponding comment
in do_coredump() (fs/exec.c). The comment explicitly states that there's
no need to check RLIMIT_CORE value because file size limits and
permissions apply as they do with any other process.

There are also no further rlimit checks in usermode helper functions, at
least I could not find any ...

- reto

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/