Linux Kernel ACPI PPTT Vulnerability in Atomic Context

A vulnerability in the Linux kernel's ACPI PPTT handling can lead to improper behavior in atomic contexts. The issue arises because the PPTT table, when absent, is not properly accounted for, causing secondary CPUs to attempt to access cache information in a context that does not allow sleeping. This oversight can trigger a kernel error related to invalid context handling.

Impact

Exploitation of this vulnerability can cause a kernel panic by invoking a sleeping function in an invalid context, disrupting normal kernel operations and potentially leading to a system crash.

Remediation

The vulnerability has been addressed in the Linux kernel by updating the ACPI PPTT handling to check for the table's presence before attempting to access it, thereby avoiding unnecessary sleeps in atomic contexts.