{"id":"CVE-2026-90195","published":"2026-09-17T17:17:14.280","lastModified":"2026-09-17T17:17:14.280","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.","cvssScore":null,"cvssSeverity":null,"cvssVector":null,"cwes":[],"vendors":[],"products":[],"references":[{"url":"https://git.kernel.org/stable/c/555fc6f1caf00ce7005e732b688da26c0dc3c5c5","tags":[]},{"url":"https://git.kernel.org/stable/c/71dbd143be598954ae103feadd12692aeb0f2f88","tags":[]},{"url":"https://git.kernel.org/stable/c/801ae90f8ce099187e6224cec7d72d07a4df0324","tags":[]},{"url":"https://git.kernel.org/stable/c/f2aaa621591093cfe8224a25ef2f04a3b1e304b0","tags":[]}],"exploitRefs":[],"hasPoc":false,"ai":null}