[PlanetCCRMA] ACL permissions for USB audio devices

[Luis Garrido]

Hi!

Recently my USB audio interface has stopped working for my
unprivileged user, there is some permission stuff going on.

kompoza at membrillo:~$ ls -l /dev/snd/
total 0
crw-rw----+ 1 root root 116, 13 2009-04-28 10:44 controlC0
crw-rw----+ 1 root root 116,  6 2009-04-28 10:44 controlC1
crw-rw----  1 root root 116, 17 2009-04-28 12:47 controlC2
crw-rw----  1 root root 116, 14 2009-04-28 12:47 midiC2D0
crw-rw----+ 1 root root 116, 12 2009-04-28 10:44 pcmC0D0c
crw-rw----+ 1 root root 116, 11 2009-04-28 12:46 pcmC0D0p
crw-rw----+ 1 root root 116, 10 2009-04-28 10:44 pcmC0D1c
crw-rw----+ 1 root root 116,  9 2009-04-28 10:44 pcmC0D2c
crw-rw----+ 1 root root 116,  8 2009-04-28 10:44 pcmC0D3c
crw-rw----+ 1 root root 116,  7 2009-04-28 10:44 pcmC0D4p
crw-rw----+ 1 root root 116,  5 2009-04-28 10:44 pcmC1D0c
crw-rw----+ 1 root root 116,  4 2009-04-28 10:44 pcmC1D0p
crw-rw----  1 root root 116, 16 2009-04-28 12:47 pcmC2D0c
crw-rw----  1 root root 116, 15 2009-04-28 12:47 pcmC2D0p
crw-rw----+ 1 root root 116,  3 2009-04-28 10:44 seq
crw-rw----+ 1 root root 116,  2 2009-04-28 10:44 timer

See the + sign at the right of the permission list? That means the
device has an ACL assigned. My integrated ICH6 card devices get that
ACL, but not the USB devices.

kompoza at membrillo:~$ getfacl /dev/snd/pcmC0D0c
getfacl: Removing leading '/' from absolute path names
# file: dev/snd/pcmC0D0c
# owner: root
# group: root
user::rw-
user:kompoza:rw-
group::rw-
mask::rw-
other::---

kompoza at membrillo:~$ getfacl /dev/snd/pcmC
pcmC0D0c  pcmC0D1c  pcmC0D3c  pcmC1D0c  pcmC2D0c
pcmC0D0p  pcmC0D2c  pcmC0D4p  pcmC1D0p  pcmC2D0p
kompoza at membrillo:~$ getfacl /dev/snd/pcmC2D0c
getfacl: Removing leading '/' from absolute path names
# file: dev/snd/pcmC2D0c
# owner: root
# group: root
user::rw-
group::rw-
other::---

I am using FC10 and this problem only popped up yesterday, so it might
have to do with some buggy updated package. Of my latest updates
initscripts seems the most likely candidate, but it could be some
dormant bug in another package that just got triggered.

I don't know who is ultimately responsible for this... udev? hal? gdm?
ConsoleKit? I am tracking it down now, but I would appreciate any
comments that point me in the right direction.

And if your USB device stopped working recently, check this out, you
might be in the same situation.

Cheers,

Luis