{"id":"CVE-2025-39990","title":"bpf: Check the helper function is valid in get_helper_proto","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Check the helper function is valid in get_helper_proto\n\nkernel test robot reported verifier bug [1] where the helper func\npointer could be NULL due to disabled con…","severity":"high","cvss":7.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","cvssSource":"cna","cwe":["CWE-476"],"vendor":"Linux","product":"Linux","affected":["Linux >= f470378c7562a2818b45ed11c98973f2b89eedd3 < dfbff47f120e4b0793ca0e0b8660361ccac25a74","Linux >= f470378c7562a2818b45ed11c98973f2b89eedd3 < 3d429cb1278e995e22995ef117fa96d223a67e93","Linux >= f470378c7562a2818b45ed11c98973f2b89eedd3 < 6233715b4b714068d6c831d214a4e8792109875a","Linux >= f470378c7562a2818b45ed11c98973f2b89eedd3 < e4414b01c1cd9887bbde92f946c1ba94e40d6d64","Linux 5.8"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2026-10-15T21:55:55.410522Z"},"published":"2025-10-15","updated":"2026-10-21","sourceUpdated":"2026-10-21T12:37:41.130Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2025-39990","references":[{"url":"https://git.kernel.org/stable/c/dfbff47f120e4b0793ca0e0b8660361ccac25a74"},{"url":"https://git.kernel.org/stable/c/3d429cb1278e995e22995ef117fa96d223a67e93"},{"url":"https://git.kernel.org/stable/c/6233715b4b714068d6c831d214a4e8792109875a"},{"url":"https://git.kernel.org/stable/c/e4414b01c1cd9887bbde92f946c1ba94e40d6d64"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2025/cve-2025-39990.json"},{"url":"https://access.redhat.com/security/cve/CVE-2025-39990"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2404114"},{"url":"https://www.cve.org/CVERecord?id=CVE-2025-39990"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2025-39990"},{"url":"https://lore.kernel.org/linux-cve-announce/2025101502-CVE-2025-39990-25bc@gregkh/T"}],"tags":["cve.org","csaf","vex","red-hat","score-dispute"],"epss":0.00193,"epssPercentile":0.08947,"scores":{"cna":7.8,"vendor":5.5},"ingestedAt":"2026-10-15T22:48:25.535Z","slug":"CVE-2025-39990","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Check the helper function is valid in get_helper_proto\n\nkernel test robot reported verifier bug [1] where the helper func\npointer could be NULL due to disabled config option.\n\nAs Alexei suggested we could check on that in get_helper_proto\ndirectly. Marking tail_call helper func with BPF_PTR_POISON,\nbecause it is unused by design.\n\n  [1] https://lore.kernel.org/oe-lkp/202507160818.68358831-lkp@intel.com\n\n## Affected\n\n- `Linux >= f470378c7562a2818b45ed11c98973f2b89eedd3 < dfbff47f120e4b0793ca0e0b8660361ccac25a74`\n- `Linux >= f470378c7562a2818b45ed11c98973f2b89eedd3 < 3d429cb1278e995e22995ef117fa96d223a67e93`\n- `Linux >= f470378c7562a2818b45ed11c98973f2b89eedd3 < 6233715b4b714068d6c831d214a4e8792109875a`\n- `Linux >= f470378c7562a2818b45ed11c98973f2b89eedd3 < e4414b01c1cd9887bbde92f946c1ba94e40d6d64`\n- `Linux 5.8`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Low · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9 · updated 2026-10-16 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2025/cve-2025-39990.json)","depth":"twilight","depthScore":43,"depthScoreParts":{"impact":42.9,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":227202,"id":"CVE-2025-39990","ts":1792587207475,"field":"cvss","old":"5.5","new":"7.8"},{"seq":227201,"id":"CVE-2025-39990","ts":1792587207475,"field":"severity","old":"medium","new":"high"},{"seq":223562,"id":"CVE-2025-39990","ts":1792238316795,"field":"cvss","old":"7.8","new":"5.5"},{"seq":223561,"id":"CVE-2025-39990","ts":1792238316795,"field":"severity","old":"high","new":"medium"}]}