CVE-2021-47429

CVE Details

Release Date:

2024-05-21

Description

In the Linux kernel, the following vulnerability has been resolved:\npowerpc/64s: Fix unrecoverable MCE calling async handler from NMI\nThe machine check handler is not considered NMI on 64s. The early\nhandler is the true NMI handler, and then it schedules the\nmachine_check_exception handler to run when interrupts are enabled.\nThis works fine except the case of an unrecoverable MCE, where the true\nNMI is taken when MSR[RI] is clear, it can not recover, so it calls\nmachine_check_exception directly so something might be done about it.\nCalling an async handler from NMI context can result in irq state and\nother things getting corrupted. This can also trigger the BUG at\narch/powerpc/include/asm/interrupt.h:168\nBUG_ON(!arch_irq_disabled_regs(regs) && !(regs->msr & MSR_EE));\nFix this by making an _async version of the handler which is called\nin the normal case, and a NMI version that is called for unrecoverable\ninterrupts.

See more information about CVE-2021-47429 from MITRE CVE dictionary and NIST NVD

CVSS Scoring

NOTE: The following CVSS v3.1 metrics and score provided are preliminary and subject to review.

Base Score:	4.4	CVSS Vector:	CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
Attack Vector:	Local network	Attack Complexity:	Low
Privileges Required:	High	User Interaction:	None
Scope:	Unchanged	Confidentiality Impact:	None
Integrity Impact:	None	Availability Impact:	High

Errata information

Platform	Errata	Release Date
Oracle Linux version 9 (kernel)	ELSA-2024-9315	2024-11-14