[Pkg-alsa-devel] Bug#251836: /etc/hotplug/blacklist.d/alsa-base is ignored by Hotplug, allowing OSS to load

[Jo Shields]

Package: alsa-base
Version: 1.0.4-3
Severity: important
Tags: sid



-- System Information:
Debian Release: testing/unstable
  APT prefers unstable
  APT policy: (500, 'unstable')
Architecture: i386 (i686)
Kernel: Linux 2.6.6-1-686
Locale: LANG=en_GB.UTF-8, LC_CTYPE=en_GB.UTF-8

Versions of packages alsa-base depends on:
ii  alsa-utils                   1.0.4-1     Advanced Linux Sound Architecture 
ii  debconf                      1.4.25      Debian configuration management sy
ii  debianutils                  2.8.2       Miscellaneous utilities specific t
ii  module-init-tools            3.0-pre10-4 tools for managing Linux kernel mo
ii  modutils                     2.4.26-1    Linux module utilities
ii  psmisc                       21.5-1      Utilities that use the proc filesy

-- debconf information:
  alsa-base/alsactl_store_on_shutdown: autosave always


-- summary
The entry made by ALSA to explicitly prevent OSS modules from loading is 
ignored (/etc/hotplug/blacklist.d/alsa-base). As a result, on kernels 
where both OSS and ALSA modules are available (such as any apt-getted 
2.6 series binary kernel), the OSS and ALSA modules are both loaded. 
alsactl will complain that it is unable to find a sound card, and sound 
will work on the system via OSS. running alsaconf will successfully 
report the card, will claim to configure the system correctly, but give 
the alsactl error at the last step.

I was unable to make Hotplug obey the blacklist entries, and eventually 
brute-forced the issue by deleting the offending kernel module from 
/lib/modules/2.6.6-1-686/kernel/sound/oss, which instantly made ALSA 
come to life.

I am unsure whether this is an alsa-base or hotplug issue, but I was 
told this was the best place for the report.