Linux Kernel up to 5.14.11 machine_check_exception state issue

Summaryinfo

A vulnerability described as problematic has been identified in Linux Kernel up to 5.14.11. This impacts the function machine_check_exception. The manipulation results in state issue. This vulnerability is cataloged as CVE-2021-47429. There is no exploit available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability, which was classified as problematic, was found in Linux Kernel up to 5.14.11. Affected is the function machine_check_exception. The manipulation with an unknown input leads to a state issue vulnerability. CWE is classifying the issue as CWE-371. The impact remains unknown. CVE summarizes:

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

The advisory is available at git.kernel.org. This vulnerability is traded as CVE-2021-47429 since 05/21/2024. Technical details are known, but there is no available exploit.

Upgrading to version 5.14.12 eliminates this vulnerability. Applying the patch d7a8e38999fb/f08fb25bc669 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

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Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 5.14.0
• 5.14.1
• 5.14.2
• 5.14.3
• 5.14.4
• 5.14.5
• 5.14.6
• 5.14.7
• 5.14.8
• 5.14.9
• 5.14.10
• 5.14.11

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

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CPE 2.2info

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