Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved:
ALSA: hda: cs35l41: validate and free ACPI mute object
cs35l41_get_acpi_mute_state() evaluates a _DSM method to get the ACPI mute state and reads the first byte from the returned object.
However, the returned ACPI object is owned by the caller and is never freed after use, so each successful query leaks the _DSM result object.
The code also assumes that the returned object is a buffer with at least one byte. A malformed firmware response can return a different object type or an empty buffer, and the direct ret->buffer.pointer dereference can then access an invalid pointer.
Use the typed _DSM helper, validate that the returned buffer contains at least one byte, and free the ACPI object after reading it.
Details
- Affected product:
- Debian 10 ELS
- Affected packages:
- linux @ 4.19.0