CVE-2022-50232 arm64: set UXN on swapper page tables
A missing UXN bit in ARM64 swapper page tables causes a kernel panic on systems with FEAT_EPAN, leading to denial of service.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2022-50232?
CVE-2022-50232 is a medium-severity denial of service vulnerability in Linux kernel, published on 18 Jun 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Official 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.
Which versions are affected by CVE-2022-50232?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2022-50232?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2022-50232 being exploited?
There is no known exploitation of CVE-2022-50232 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as DEBIAN-CVE-2022-50232, GHSA-7m8m-mqvx-9vwv, ROOT-OS-UBUNTU-2204-CVE-2022-50232, ROOT-OS-UBUNTU-2404-CVE-2022-50232, UBUNTU-CVE-2022-50232.