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 for Android: free password hash cracker in your pocket
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <Pine.LNX.4.64.0706072216560.3454@alien.or.mcafeemobile.com>
Date:	Thu, 7 Jun 2007 22:20:22 -0700 (PDT)
From:	Davide Libenzi <davidel@...ilserver.org>
To:	Eric Dumazet <dada1@...mosbay.com>
cc:	Kyle Moffett <mrmacman_g4@....com>,
	Alan Cox <alan@...rguk.ukuu.org.uk>,
	Ulrich Drepper <drepper@...hat.com>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Ingo Molnar <mingo@...e.hu>
Subject: Re: [patch 7/8] fdmap v2 - implement sys_socket2

On Fri, 8 Jun 2007, Eric Dumazet wrote:

> Davide Libenzi a écrit :
> > On Thu, 7 Jun 2007, Eric Dumazet wrote:
> > > I am afraid randomization wont really work if /sbin/init or /bin/bash for
> > > example uses one (or more) unseq fd :
> > > The 'random base' will be propagated at fork()/exec() time ?
> > 
> > As I said to Uli, we can't move the base while fds are in there. We can
> > re-randomize it when it's empty. This can also be done (it's a trivial and
> > fast operation - just set fmap->base to a new value) even every time the fd
> > count on the map touches zero.
> > 
> 
> Hum, I think it would be better to free fmap if it's empty, instead of change
> fmap->base. (Only in fork() after removal of O_CLOFORK file handles, and in
> exec() after removal of O_CLOEXEC file handles)

That can be done too. When it'll be re-created will be randomized anyway.
I'll probably be doing it everytime fmap->count touches zero in 
__put_unused_fd(), so even if the map is not empty at fork and/or exec 
time, the program have other chances of randomize in the middle of its 
lifetime.


- Davide


Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ