In the Linux kernel, the following vulnerability has been resolved: ALSA: hda/cs_dsp_ctl: Use private_free for control cleanup Use the control private_free callback to free the associated data block. This ensures that the memory won't leak, whatever way the control gets destroyed. The original implementation didn't actually remove the ALSA controls in hda_cs_dsp_control_remove(). It only freed the internal tracking structure. This meant it was possible to remove/unload the amp driver while leaving its ALSA controls still present in the soundcard. Obviously attempting to access them could cause segfaults or at least dereferencing stale pointers.
https://git.kernel.org/stable/c/6e359be4975006ff72818e79dad8fe48293f2eb2
https://git.kernel.org/stable/c/3291486af5636540980ea55bae985f3eaa5b0740
https://git.kernel.org/stable/c/191dc1b2ff0fb35e7aff15a53224837637df8bff
https://git.kernel.org/stable/c/172811e3a557d8681a5e2d0f871dc04a2d17eb13