Local service disruption via unguarded PTE marker paths
Published Oct 1, 2025 · Updated Oct 1, 2025
Denial of service in Linux 5.19 through 5.19.16 and 6.0 through 6.0.2 allows local users to trigger a kernel warning via userfaultfd. The hugetlb unmap, zap, and mprotect paths execute UFFD write-protect PTE marker operations without CONFIG_PTE_MARKER_UFFD_WP guards, reaching WARN_ON_ONCE on an unexpected nonempty PTE. Exploitation requires local low-privileged access and a kernel built without that option; the observed consequence is a warning and availability loss, not data access or modification.
Summary
What happened
Denial of service in Linux 5.19 through 5.19.16 and 6.0 through 6.0.2 allows local users to trigger a kernel warning via userfaultfd. The hugetlb unmap, zap, and mprotect paths execute UFFD write-protect PTE marker operations without CONFIG_PTE_MARKER_UFFD_WP guards, reaching WARN_ON_ONCE on an unexpected nonempty PTE. Exploitation requires local low-privileged access and a kernel built without that option; the observed consequence is a warning and availability loss, not data access or modification.
The record
- CVE
- CVE-2022-50448
- Published
- Oct 1, 2025
- Updated
- Oct 1, 2025
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- T1499
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Oct 1, 2025CVE publishedPublication date reported by the CVE source.
- Oct 1, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=5.19
- Affected versionversion=b1f9e876862d8f7176299ec4fb2108bc1045cbc8 <2204a880cb0c51952463a24a4fa01a6514c5a25a
- Affected versionversion=b1f9e876862d8f7176299ec4fb2108bc1045cbc8 <515778e2d790652a38a24554fdb7f21420d91efc
- Affected versionversion=b1f9e876862d8f7176299ec4fb2108bc1045cbc8 <b76e4eb02e9edb9a0a51942acdb373ca01346e8c
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- syzkaller C reproducer for WARNING in change_protectionproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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