In the Linux kernel, the following vulnerability has been resolved:
ASoC: wm_adsp: Fix NULL dereference when removing firmware controls
In wm_adsp_control_remove() check that the priv pointer is not NULL
before attempting to cleanup what it points to.
When cs_dsp creates a control it calls wm_adsp_control_add_cb() so that
wm_adsp can create its own private control data. There are two cases
where private data is not created:
-
The control is a SYSTEM control, so an ALSA control is not created.
-
The codec driver has registered a control_add() callback that
hides the control, so wm_adsp_control_add() is not called.
When cs_dsp_remove destroys its control list it calls
wm_adsp_control_remove() for each control. But wm_adsp_control_remove()
was attempting to cleanup the private data pointed to by cs_ctl->priv
without checking the pointer for NULL.