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CVE-2022-50232

MEDIUMCVSS 5.5/10EPSS 0.17%

Last modified

CVE-2022-50232 is a medium-severity vulnerability rated 5.5/10 on the CVSS scale. In the Linux kernel, the following vulnerability has been resolved: arm64: set UXN on swapper page tables [ This issue was fixed upstream by accident in c3cee924bd85 ("arm64: head: cover entire kernel image in initial ID map") as part of a large refactoring of the arm64 boot flow. This simple fix is therefore preferred for -stable backporting ] On a system that implements FEAT_EPAN, read/write access to the idmap is denied because UXN is not set on the swapper PTEs. EPSS estimates a 0.17% chance of exploitation in the next 30 days.

Description

In the Linux kernel, the following vulnerability has been resolved: arm64: set UXN on swapper page tables [ This issue was fixed upstream by accident in c3cee924bd85 ("arm64: head: cover entire kernel image in initial ID map") as part of a large refactoring of the arm64 boot flow. This simple fix is therefore preferred for -stable backporting ] On a system that implements FEAT_EPAN, read/write access to the idmap is denied because UXN is not set on the swapper PTEs. As a result, idmap_kpti_install_ng_mappings panics the kernel when accessing __idmap_kpti_flag. Fix it by setting UXN on these PTEs.

Metrics

CVSS 3.1
5.5/10

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

EPSS Probability
0.17%

6.5th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

VendorProductVersions
LinuxLinux Kernel>= 5.13, < 5.15.60
LinuxLinux Kernel>= 5.16, < 6.0

References

Timeline

Published
Last Modified
Status
Analyzed

Frequently Asked Questions

What is CVE-2022-50232?
In the Linux kernel, the following vulnerability has been resolved: arm64: set UXN on swapper page tables [ This issue was fixed upstream by accident in c3cee924bd85 ("arm64: head: cover entire kernel image in initial ID map") as part of a large refactoring of the arm64 boot flow. This simple fix is therefore preferred for -stable backporting ] On a system that implements FEAT_EPAN, read/write access to the idmap is denied because UXN is not set on the swapper PTEs. As a result, idmap_kpti_install_ng_mappings panics the kernel when accessing __idmap_kpti_flag. Fix it by setting UXN on these PTEs.
How severe is CVE-2022-50232?
CVE-2022-50232 has a CVSS score of 5.5/10 (MEDIUM severity). The EPSS model estimates a 0.17% probability of exploitation in the next 30 days.
How do I fix CVE-2022-50232?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2022-50232?

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Source: NVD / NIST