bpf: Check the helper function is valid in get_helper_proto
In the Linux kernel, the following vulnerability has been resolved: bpf: Check the helper function is valid in get_helper_proto kernel test robot reported verifier bug [1] where the helper func pointer could be NULL due to disabled config option. As Alexei suggested we could check on that in get_helper_proto directly. Marking tail_call helper func with BPF_PTR_POISON, because it is unused by design. [1] https://lore.kernel.org/oe-lkp/[email protected]
02 / AFFECTED SOFTWARE
Affected packages
03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
In the Linux kernel, the following vulnerability has been resolved: bpf: Check the helper function is valid in get_helper_proto kernel test robot reported verifier bug [1] where the helper func pointer could be NULL due to disabled config option. As Alexei suggested we could check on that in get_helper_proto directly. Marking tail_call helper func with BPF_PTR_POISON, because it is unused by design. [1] https://lore.kernel.org/oe-lkp/[email protected]
05 / REFERENCES
Further evidence
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- https://git.kernel.org/stable/c/3d429cb1278e995e22995ef117fa96d223a67e93
- https://git.kernel.org/stable/c/6233715b4b714068d6c831d214a4e8792109875a
- https://git.kernel.org/stable/c/e4414b01c1cd9887bbde92f946c1ba94e40d6d64
- https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/39xxx/CVE-2025-39990.json
- https://nvd.nist.gov/vuln/detail/CVE-2025-39990