Vulnerability Description
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.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Linux | Linux Kernel | >= 5.14, < 5.14.12 |
References
- https://git.kernel.org/stable/c/d7a8e38999fbd6910516e44cb43f9f4317e54f73Patch
- https://git.kernel.org/stable/c/f08fb25bc66986b0952724530a640d9970fa52c1Patch
- https://git.kernel.org/stable/c/d7a8e38999fbd6910516e44cb43f9f4317e54f73Patch
- https://git.kernel.org/stable/c/f08fb25bc66986b0952724530a640d9970fa52c1Patch
FAQ
What is CVE-2021-47429?
CVE-2021-47429 is a vulnerability with a CVSS score of 5.5 (MEDIUM). 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 earl...
How severe is CVE-2021-47429?
CVE-2021-47429 has been rated MEDIUM with a CVSS base score of 5.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2021-47429?
Check the references section above for vendor advisories and patch information. Affected products include: Linux Linux Kernel.