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>] [<thread-prev] [day] [month] [year] [list]
Date:   Wed, 04 Apr 2018 18:59:08 -0500
From: (Eric W. Biederman)
To:     Alexey Dobriyan <>
Subject: Re: [PATCH] [RFC][WIP] namespace.c: Allow some unprivileged proc mounts when not fully visible

Alexey Dobriyan <> writes:

>> The only option I have seen proposed that might qualify as something
>> general purpose and simple is a new filesystem that is just the process
>> directories of proc.
> While "mount -t pid" and "mount -t sysctl" are decades overdue, I don't
> think they cover everything.
> IIRC some gcc versions read /proc/meminfo on every invocation. Now
> imagine such program doesn't have a fallback if /proc/ doesn't exist
> (how many thousands such programs are there?) So user is going to ask
> for /proc with just /proc/meminfo only. At this point it is back to
> nearly full /proc.

To avoid falling susceptible to the kinds of checks in fs_fully_visible we
can only offer information about objects that root in the user namespace
has privilege over.  So "mount -t pid" good.  A "/proc/meminfo" bad.

Which in short means if "mount -t pid" isn't good enough.  There really
isn't anything the kernel can do.


Powered by blists - more mailing lists