{"cve":"CVE-2026-90195","nvd":{"published":"2026-09-17T17:17:14.280","modified":"2026-10-19T09:19:09.510","status":"Received","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nriscv, bpf: Fix missing sign-ext for signed 1-byte and 2-byte kfunc args\n\nOn RV64, the ABI requires sign-extension for signed 1-byte and 2-byte kfunc\nargs. However, the RV64 JIT currently does not perform sign-extension for\nsuch kfunc args.\n\nBefore commit 7ce090afbf72 (\"bpf: Infer zext_dst based on static register\nliveness analysis\"), state pruning could potentially omit zero-extension\nof 32-bit subregisters, which inadvertently masked the above issue by making\nthe args appear as if they had been properly sign-extended. After that\ncommit, the problem is exposed, causing the kfunc_call/kfunc_call_test4\nselftest to fail.\n\nFix this by extending the existing sign-extension logic to handle signed\n1-byte and 2-byte kfunc args as well.","cvss_v4":null,"cvss_v3":null,"cwes":[],"references":["https://git.kernel.org/stable/c/555fc6f1caf00ce7005e732b688da26c0dc3c5c5","https://git.kernel.org/stable/c/71dbd143be598954ae103feadd12692aeb0f2f88","https://git.kernel.org/stable/c/801ae90f8ce099187e6224cec7d72d07a4df0324","https://git.kernel.org/stable/c/f2aaa621591093cfe8224a25ef2f04a3b1e304b0"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:55:23.253742848+00:00"},"epss":{"cve":"CVE-2026-90195","score":0.00209,"percentile":0.10912,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}