CVE-2024-36926

/// Technical description

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

powerpc/pseries/iommu: LPAR panics during boot up with a frozen PE

At the time of LPAR boot up, partition firmware provides Open Firmware

property ibm,dma-window for the PE. This property is provided on the PCI

bus the PE is attached to.

There are execptions where the partition firmware might not provide this

property for the PE at the time of LPAR boot up. One of the scenario is

where the firmware has frozen the PE due to some error condition. This

PE is frozen for 24 hours or unless the whole system is reinitialized.

Within this time frame, if the LPAR is booted, the frozen PE will be

presented to the LPAR but ibm,dma-window property could be missing.

Today, under these circumstances, the LPAR oopses with NULL pointer

dereference, when configuring the PCI bus the PE is attached to.

BUG: Kernel NULL pointer dereference on read at 0x000000c8

Faulting instruction address: 0xc0000000001024c0

Oops: Kernel acce

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References