Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved: kvm: LAPIC: Restore guard to prevent illegal APIC register access Per the SDM, "any access that touches bytes 4 through 15 of an APIC register may cause undefined behavior and must not be executed." Worse, such an access in kvm_lapic_reg_read can result in a leak of kernel stack contents. Prior to commit 01402cf81051 ("kvm: LAPIC: write down valid APIC registers"), such an access was explicitly disallowed. Restore the guard that was removed in that commit.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Linux | Linux Kernel | >= 5.3, < 5.4.128 |
References
- https://git.kernel.org/stable/c/018685461a5b9a9a70e664ac77aef0d7415a3fd5Patch
- https://git.kernel.org/stable/c/218bf772bddd221489c38dde6ef8e917131161f6Patch
- https://git.kernel.org/stable/c/a2aff09807fbe4018c269d3773a629949058b210Patch
- https://git.kernel.org/stable/c/bf99ea52970caeb4583bdba1192c1f9b53b12c84Patch
- https://git.kernel.org/stable/c/018685461a5b9a9a70e664ac77aef0d7415a3fd5Patch
- https://git.kernel.org/stable/c/218bf772bddd221489c38dde6ef8e917131161f6Patch
- https://git.kernel.org/stable/c/a2aff09807fbe4018c269d3773a629949058b210Patch
- https://git.kernel.org/stable/c/bf99ea52970caeb4583bdba1192c1f9b53b12c84Patch
FAQ
What is CVE-2021-47255?
CVE-2021-47255 is a vulnerability with a CVSS score of 7.1 (HIGH). In the Linux kernel, the following vulnerability has been resolved: kvm: LAPIC: Restore guard to prevent illegal APIC register access Per the SDM, "any access that touches bytes 4 through 15 of an A...
How severe is CVE-2021-47255?
CVE-2021-47255 has been rated HIGH with a CVSS base score of 7.1/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2021-47255?
Check the references section above for vendor advisories and patch information. Affected products include: Linux Linux Kernel.