In the Linux kernel, the following vulnerability has been resolved: bpf: Check the helper function is valid in get_helper_proto kernel test robot… (CVE-2025-39990)
A high severity vulnerability in the Linux kernel related to the BPF subsystem was resolved. The issue involved a verifier bug where a helper function pointer could be NULL due to a disabled configuration option. The fix involves validating the helper function directly in get_helper_proto and marking the tail_call helper function as poisoned since it is unused by design.
AI Analysis
Technical Summary
CVE-2025-39990 addresses a vulnerability in the Linux kernel's BPF subsystem where the verifier could encounter a NULL helper function pointer caused by a disabled config option. This could lead to incorrect behavior or potential security issues. The resolution includes adding a check in get_helper_proto to ensure the helper function is valid and marking the tail_call helper function with BPF_PTR_POISON to prevent its use, as it is intentionally unused.
Potential Impact
The vulnerability could allow local attackers with limited privileges to cause high impact on confidentiality, integrity, and availability of the system due to the verifier bug in the BPF helper function handling. The CVSS vector indicates local attack vector, low attack complexity, low privileges required, no user interaction, unchanged scope, and high impact on confidentiality, integrity, and availability.
Mitigation Recommendations
A fix has been implemented in the Linux kernel to address this vulnerability by validating the helper function in get_helper_proto and marking the tail_call helper function as poisoned. Users should apply the official Linux kernel updates that include this fix. Patch status is not explicitly confirmed in the provided data; therefore, check the vendor advisory or Linux kernel mailing lists for the latest remediation guidance.
In the Linux kernel, the following vulnerability has been resolved: bpf: Check the helper function is valid in get_helper_proto kernel test robot… (CVE-2025-39990)
Description
A high severity vulnerability in the Linux kernel related to the BPF subsystem was resolved. The issue involved a verifier bug where a helper function pointer could be NULL due to a disabled configuration option. The fix involves validating the helper function directly in get_helper_proto and marking the tail_call helper function as poisoned since it is unused by design.
CVSS v3.1
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2025-39990 addresses a vulnerability in the Linux kernel's BPF subsystem where the verifier could encounter a NULL helper function pointer caused by a disabled config option. This could lead to incorrect behavior or potential security issues. The resolution includes adding a check in get_helper_proto to ensure the helper function is valid and marking the tail_call helper function with BPF_PTR_POISON to prevent its use, as it is intentionally unused.
Potential Impact
The vulnerability could allow local attackers with limited privileges to cause high impact on confidentiality, integrity, and availability of the system due to the verifier bug in the BPF helper function handling. The CVSS vector indicates local attack vector, low attack complexity, low privileges required, no user interaction, unchanged scope, and high impact on confidentiality, integrity, and availability.
Mitigation Recommendations
A fix has been implemented in the Linux kernel to address this vulnerability by validating the helper function in get_helper_proto and marking the tail_call helper function as poisoned. Users should apply the official Linux kernel updates that include this fix. Patch status is not explicitly confirmed in the provided data; therefore, check the vendor advisory or Linux kernel mailing lists for the latest remediation guidance.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-2m9q-5w5g-jwfp
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2025-39990"]
- Ecosystems
- []
- Database Specific Severity
- HIGH
- Cvss Version
- 3.1
Threat ID: 6a6b72d89c2644c7f847be40
Added to database: 07/30/2026, 15:50:48 UTC
Last enriched: 07/30/2026, 15:52:23 UTC
Last updated: 07/30/2026, 16:23:41 UTC
Views: 5
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