CVE-2022-49440

Name of the Vulnerable Software and Affected Versions Linux kernel versions prior to the version where the MSR[RI] issue is fixed

Description The issue arises from the Linux kernel's handling of the MSR[RI] bit when calling RTAS. RTAS is expected to be called with MSR[RI] set as specified in the PAPR+ section "7.2.1 Machine State". However, the kernel unsets MSR[RI] when entering RTAS without a valid reason. This can lead to a panic when hitting the watchdog interrupt while running in RTAS, resulting in an unrecoverable system reset. The estimated number of potentially affected devices is not provided.

Recommendations As a temporary workaround, consider reviewing and adjusting the MSR computation before calling RTAS to ensure MSR[RI] is set correctly. At the moment, there is no information about a newer version that contains a fix for this vulnerability.