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.

References

• https://nvd.nist.gov/vuln/detail/CVE-2022-50230
• https://git.kernel.org/stable/c/9283e708a9b8529e7aafac9ab5c5c79a9fab8846