Host crash via misaddressed KVM page-table update
Published Aug 5, 2022 · Updated Aug 2, 2024
Use-after-free in KVM in Linux Kernel 5.18 allows local users to corrupt kernel memory through a guest page-table update. In cmpxchg_gpte, a failed page pin drives memremap with a PFN computed from attacker-controlled vaddr and vm_pgoff, then CMPXCHG writes to the resulting out-of-region address. Access to /dev/kvm is required; the demonstrated result is a use-after-free write and endless page walking that can crash the host, while privilege escalation remains only potential.
Summary
What happened
Use-after-free in KVM in Linux Kernel 5.18 allows local users to corrupt kernel memory through a guest page-table update. In cmpxchg_gpte, a failed page pin drives memremap with a PFN computed from attacker-controlled vaddr and vm_pgoff, then CMPXCHG writes to the resulting out-of-region address. Access to /dev/kvm is required; the demonstrated result is a use-after-free write and endless page walking that can crash the host, while privilege escalation remains only potential.
The record
- CVE
- CVE-2022-1158
- Published
- Aug 5, 2022
- Updated
- Aug 2, 2024
- Vendor
- The Linux Kernel Organization
- Product
- Linux Kernel
- Classifications
- CWE-416, T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Aug 5, 2022CVE publishedPublication date reported by the CVE source.
- Aug 2, 2024Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
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- Affected versionversion=kernel 5.18
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.
Public exploit references
- KVM io_uring guest-memory reproducerproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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