Incomplete Cleanup Affecting kernel-rt package, versions *

Note: Versions mentioned in the description apply only to the upstream kernel-rt package and not the kernel-rt package as distributed by Centos. See How to fix? for Centos:7 relevant fixed versions and status.

In the Linux kernel, the following vulnerability has been resolved:

ALSA: hda: Do not unset preset when cleaning up codec

Several functions that take part in codec's initialization and removal are re-used by ASoC codec drivers implementations. Drivers mimic the behavior of hda_codec_driver_probe/remove() found in sound/pci/hda/hda_bind.c with their component->probe/remove() instead.

One of the reasons for that is the expectation of snd_hda_codec_device_new() to receive a valid pointer to an instance of struct snd_card. This expectation can be met only once sound card components probing commences.

As ASoC sound card may be unbound without codec device being actually removed from the system, unsetting ->preset in snd_hda_codec_cleanup_for_unbind() interferes with module unload -> load scenario causing null-ptr-deref. Preset is assigned only once, during device/driver matching whereas ASoC codec driver's module reloading may occur several times throughout the lifetime of an audio stack.

• https://access.redhat.com/security/cve/CVE-2023-52736
• https://git.kernel.org/stable/c/427ca2530da8dc61a42620d7113b05e187b6c2c0
• https://git.kernel.org/stable/c/7fc4e7191eae9d9325511e03deadfdb2224914f8
• https://git.kernel.org/stable/c/87978e6ad45a16835cc58234451111091be3c59a
• https://git.kernel.org/stable/c/e909f5f2aa55a8f9aa6919cce08015cb0e8d4668