CVE-2022-50870

/// Technical description

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

powerpc/rtas: avoid device tree lookups in rtas_os_term()

rtas_os_term() is called during panic. Its behavior depends on a couple

of conditions in the /rtas node of the device tree, the traversal of

which entails locking and local IRQ state changes. If the kernel panics

while devtree_lock is held, rtas_os_term() as currently written could

hang.

Instead of discovering the relevant characteristics at panic time,

cache them in file-static variables at boot. Note the lookup for

"ibm,extended-os-term" is converted to of_property_read_bool() since it

is a boolean property, not an RTAS function token.

[mpe: Incorporate suggested change from Nick]

/// 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