CVE-2022-49402

Kernel crash via stale ftrace direct-function entry

Published Feb 26, 2025 · Updated May 11, 2026

Denial of service in Linux kernel ftrace before 5.19 allows local users to crash the kernel through repeated BPF tracing. A failed register_ftrace_direct call leaves its entry in the direct_functions hash, so a second lookup dereferences stale state and causes a general protection fault. A livepatch must already cover the traced function, and the user must be permitted to attach the BPF tracing program; the consequence is limited to a kernel crash.

CVSS severity5.5
Medium
EPSS probability0.28%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in Linux kernel ftrace before 5.19 allows local users to crash the kernel through repeated BPF tracing. A failed register_ftrace_direct call leaves its entry in the direct_functions hash, so a second lookup dereferences stale state and causes a general protection fault. A livepatch must already cover the traced function, and the user must be permitted to attach the BPF tracing program; the consequence is limited to a kernel crash.

The record

CVE
CVE-2022-49402
Published
Feb 26, 2025
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 26, 2025CVE publishedPublication date reported by the CVE source.
  2. May 11, 2026Record 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.

  1. Affected versionversion=5.5
  2. Affected versionversion=763e34e74bb7d5c316015e2e39fcc8520bfd071c <7d54c15cb89a29a5f59e5ffc9ee62e6591769ef1
  3. Affected versionversion=763e34e74bb7d5c316015e2e39fcc8520bfd071c <805e87af946d8d2954171361e64d143ff37a441b
  4. Affected versionversion=763e34e74bb7d5c316015e2e39fcc8520bfd071c <82c888e51c2176a06f8b4541cf748ee81aac6e7e
  5. Affected versionversion=763e34e74bb7d5c316015e2e39fcc8520bfd071c <a0392833a178cf109a57c2a9d4d531bdfc6cd98f
  6. Affected versionversion=763e34e74bb7d5c316015e2e39fcc8520bfd071c <cae2978d6907ef2c08b9b15f704e783f7c284713

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.5; version=763e34e74bb7d5c316015e2e39fcc8520bfd071c <7d54c15cb89a29a5f59e5ffc9ee62e6591769ef1; version=763e34e74bb7d5c316015e2e39fcc8520bfd071c <805e87af946d8d2954171361e64d143ff37a441b; version=763e34e74bb7d5c316015e2e39fcc8520bfd071c <82c888e51c2176a06f8b4541cf748ee81aac6e7e; version=763e34e74bb7d5c316015e2e39fcc8520bfd071c <a0392833a178cf109a57c2a9d4d531bdfc6cd98f; version=763e34e74bb7d5c316015e2e39fcc8520bfd071c <cae2978d6907ef2c08b9b15f704e783f7c284713

Published CVSS scores

5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

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.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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