2 Nov
2005
2 Nov
'05
6:25 a.m.
Hello Lists,
I don't know, where ich can fix my little problem. Maybe i 've missed some
explanations and/or haven't read my mails good enough. anyway, i try to
install a linuxbox for audio on slackware
i have installed slackware and patching the kernel 2.6.14 vanilla with
patch-2.6.14-rt2. Then i installed the set_rtlimits1.1.0 software, because
Slackware has no PAM.
First. this must be all for audio in realtime , is this right??
then i have to set the setuid. aus root i have done
bash-3.00$ su
Password:
bash-3.00# chmod ugo+s /usr/local/bin/jackd
bash-3.00# exit
bash-3.00$ ls -la /usr/local/bin/jackd
-rwsr-sr-x 1 root root 206476 2005-11-01 15:23 /usr/local/bin/jackd
bash-3.00$ whoami
soundroom
bash-3.00$ jackd -dalsa&
[1] 3202
bash-3.00$ jackd 0.100.0
Copyright 2001-2005 Paul Davis and others.
jackd comes with ABSOLUTELY NO WARRANTY
This is free software, and you are welcome to redistribute it
under certain conditions; see the file COPYING for details
JACK compiled with System V SHM support.
loading driver ..
creating alsa driver ... hw:0|hw:0|1024|2|48000|0|0|nomon|swmeter|-|32bit
control device hw:0
configuring for 48000Hz, period = 1024 frames, buffer = 2 periods
nperiods = 2 for capture
nperiods = 2 for playback
bash-3.00$ ps -aux
[..]
root 3202 0.0 0.4 10472 2380 pts/1 S 12:03 0:00 jackd -dalsa
root 3203 0.0 0.4 10472 2380 pts/1 R 12:03 0:00 jackd -dalsa
root 3204 0.0 0.4 10472 2380 pts/1 S 12:03 0:00 jackd -dalsa
root 3205 0.0 0.4 10472 2380 pts/1 S 12:03 0:00 jackd -dalsa
root 3206 0.2 0.4 10472 2380 pts/1 S 12:03 0:00 jackd -dalsa
[..]
bash-3.00$ jack_lsp
JACK server not running
why i can't use jack an normal user? what have i missed? why there are 5
processes of jack? is this a secure way? do i need every application as suid?
2 Nov
2 Nov
6:56 a.m.
On Wed, 2005-11-02 at 12:21 +0100, conrad berhörster wrote:
--
mvh // Jens M Andreasen
bash-3.00$ jack_lsp
JACK server not running
why i can't use jack an normal user? what have i missed? why there are 5
processes of jack? is this a secure way? do i need every application as suid?
Yes. The jackd and your application needs to belong to the same user. So
in order for the suid strategy to work, all your jack applications must
also be suid. Not all applications can run as suid root because the
underlying UI will not allow it.
If you have source, try the inserting the following before starting any
UI thread:
/**
* Give back ownership to the real user,
* so that we don't fuck up the machine while
* posing as root.
*
*/
setreuid(getuid(), getuid());
While we are at it; there is a bug in some some versions of libpthread,
causing the new UI thread to inherit RT capabilities set in the calling
thread. Workaround, explicitly turn it off as in:
pthread_attr_init(&i_thread_attr);
// We do not want to paint pixels at insane speeds
pthread_attr_setinheritsched(&i_thread_attr,PTHREAD_EXPLICIT_SCHED);
pthread_create(&i_thread,&i_thread_attr,interface,NULL);
8 a.m.
New subject: [linux-audio-dev] Re: [linux-audio-user] jack and setuid
bash-3.00# chmod ugo+s /usr/local/bin/jackd
bash-3.00# exit
bash-3.00$ ls -la /usr/local/bin/jackd
-rwsr-sr-x 1 root root 206476 2005-11-01 15:23 /usr/local/bin/jackd
this is a really, really, really bad thing to do. there is no reason to
run jackd as root or set it up as setuid root. you should be using some
kernel-based technique that allows you to get realtime priviledges
without being root (capabilities on 2.4 kernels, realtime-lsm for 2.6.12
or lower, or the new rtlimits code for 2.6.13 or above). if you cannot
do that, then just run without realtime or explicitly run all JACK apps
as root. do NOT install random, non-security related applications as
setuid root.
--p
8:29 a.m.
New subject: [linux-audio-dev] Re: [linux-audio-user] jack and setuid
Am Mittwoch, 2. November 2005 14:02 schrieb Paul Davis:
thanks paul,
yes, i have read that, because
of security. but don't know a better way.
bash-3.00#
chmod ugo+s /usr/local/bin/jackd
bash-3.00# exit
bash-3.00$ ls -la /usr/local/bin/jackd
-rwsr-sr-x 1 root root 206476 2005-11-01 15:23 /usr/local/bin/jackd
this is a really, really, really bad thing to do. there is no reason to
run jackd as root or set it up as setuid root. you should be using some
kernel-based technique that allows you to get realtime priviledges
without being root (capabilities on 2.4 kernels, realtime-lsm for 2.6.12
or lower, or the new rtlimits code for 2.6.13 or above).
since i'm using
2.6.14 , you mean set_rtlimits from
http://www.physics.adelaide.edu.au/~jwoithe/set_rtlimits-1.1.0.tgz ?
but if i run jack as a user, there are no capture ports, and i have tons of
xruns.
sizu c~
12:38 p.m.
New subject: [linux-audio-dev] Re: [linux-audio-user] jack and setuid
On Wed, 2 Nov 2005 14:25:45 +0100
conrad berhörster <conrad.berhoerster(a)gmx.de> wrote:
Am Mittwoch, 2. November 2005 14:02 schrieb Paul
Davis:
thanks paul,
yes, i have read that, because
of security. but don't know a better way.
Just for completeness sake: You can use the realtime lsm for 2.6.13 and
above, too. I would even recommend it, since it's much less of a hassle
to setup (rt_limits being the "correct" solution or not).
Flo
--
Palimm Palimm!
http://tapas.affenbande.org
bash-3.00# chmod ugo+s /usr/local/bin/jackd
bash-3.00# exit
bash-3.00$ ls -la /usr/local/bin/jackd
-rwsr-sr-x 1 root root 206476 2005-11-01 15:23 /usr/local/bin/jackd
this is a really, really, really bad thing to do. there is no reason to
run jackd as root or set it up as setuid root. you should be using some
kernel-based technique that allows you to get realtime priviledges
without being root (capabilities on 2.4 kernels, realtime-lsm for 2.6.12
or lower, or the new rtlimits code for 2.6.13 or above).
since i'm using
2.6.14 , you mean set_rtlimits from
http://www.physics.adelaide.edu.au/~jwoithe/set_rtlimits-1.1.0.tgz ?
but if i run jack as a user, there are no capture ports, and i have tons of
xruns.
12:49 p.m.
New subject: [linux-audio-dev] Re: [linux-audio-user] jack and setuid
Am Mittwoch, 2. November 2005 18:38 schrieb Florian Schmidt:
Just for completeness sake: You can use the realtime lsm for 2.6.13 and
above, too. I would even recommend it, since it's much less of a hassle
to setup (rt_limits being the "correct" solution or not).
Flo
Just to be sure . Do you mean lsm instead of rt_limits or both.
and do you have a link for the lsm patch.
sizu c~
1:35 p.m.
New subject: [linux-audio-dev] Re: [linux-audio-user] jack and setuid
On Wed, 2 Nov 2005 18:46:03 +0100
conrad berhörster <conrad.berhoerster(a)gmx.de> wrote:
Am Mittwoch, 2. November 2005 18:38 schrieb Florian Schmidt:
yep, instead of rt_limits (they both achieve the same goal with vastly
different approaches).
http://sourceforge.net/projects/realtime-lsm/
--
Palimm Palimm!
http://tapas.affenbande.org
Just for completeness sake: You can use the realtime lsm for 2.6.13 and
above, too. I would even recommend it, since it's much less of a hassle
to setup (rt_limits being the "correct" solution or not).
Flo
Just to be sure . Do you mean lsm instead of rt_limits or both.
and do you have a link for the lsm patch.
sizu c~
6755
days inactive
6755
days old
linux-audio-dev@lists.linuxaudio.org
6 comments
4 participants
participants (4)
-
conrad berhörster -
Florian Schmidt -
Jens M Andreasen -
Paul Davis