CVE-2021-47362

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

drm/amd/pm: Update intermediate power state for SI

Update the current state as boot state during dpm initialization. During the subsequent initialization, set_power_state gets called to transition to the final power state. set_power_state refers to values from the current state and without current state populated, it could result in NULL pointer dereference.

For ex: on platforms where PCI speed change is supported through ACPI ATCS method, the link speed of current state needs to be queried before deciding on changing to final power states link speed. The logic to query ATCS-support was broken on certain platforms. The issue became visible when broken ATCS-support logic got fixed with commit f9b7f3703ff9 (drm/amdgpu/acpi: make ATPX/ATCS structures global (v2)).

Bug: https://gitlab.freedesktop.org/drm/amd/-/issues/1698

Affected Software

References

• https://git.kernel.org/stable/c/06a18e64256f7aecb5a27df02faa3568fcd3c105
• https://git.kernel.org/stable/c/68d4fbe6220cd1f3d07cab0a4901e62f8c12cc68
• https://git.kernel.org/stable/c/ab39d3cef526ba09c4c6923b4cd7e6ec1c5d4faa