Kernel data disclosure via unchecked BPF tail-call index
Published Sep 9, 2022 · Updated Aug 3, 2024
An out-of-bounds read in Linux Kernel 5.5 through 6.0-rc3 allows local users to read kernel data through a crafted BPF tail call. The verifier derives the tail-call key range with tnum_range, whose over-approximation lets an index above max_entries pass before the x86 JIT indexes bpf_array->ptr out of bounds. Exploitation requires local BPF program loading; default Ubuntu kernels disable unprivileged BPF, so that configuration requires administrative privileges.
Summary
What happened
An out-of-bounds read in Linux Kernel 5.5 through 6.0-rc3 allows local users to read kernel data through a crafted BPF tail call. The verifier derives the tail-call key range with tnum_range, whose over-approximation lets an index above max_entries pass before the x86 JIT indexes bpf_array->ptr out of bounds. Exploitation requires local BPF program loading; default Ubuntu kernels disable unprivileged BPF, so that configuration requires administrative privileges.
The record
- CVE
- CVE-2022-2905
- Published
- Sep 9, 2022
- Updated
- Aug 3, 2024
- Vendor
- The Linux Kernel Organization
- Product
- Linux Kernel
- Classifications
- CWE-125, T1005
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Sep 9, 2022CVE publishedPublication date reported by the CVE source.
- Aug 3, 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?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=Linux kernel 6.0-rc4
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
- BPF tail-call out-of-bounds read proof of conceptproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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