{"id":"CVE-2026-98638","title":"KVM: arm64: Validate the SVE vector length in pkvm_vcpu_init_sve()","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: arm64: Validate the SVE vector length in pkvm_vcpu_init_sve()\n\npkvm_vcpu_init_sve() clamps only the upper bound of the host-provided\nsve_max_vl, so an invalid vect…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= 5db1bef933427aa467ad89c7b695a84a6b4afe16 < faf66e55e87498ab4bf88cdf9a629e61b3f2d3bc","Linux >= 5db1bef933427aa467ad89c7b695a84a6b4afe16 < bae3e4493046de4fefa15f809d9b8dc114e84a3d","Linux >= 5db1bef933427aa467ad89c7b695a84a6b4afe16 < 2a2eb10795a1e495aebc7f829ccecb72c05b4fd9","Linux 6.16"],"published":"2026-10-18","updated":"2026-10-19","sourceUpdated":"2026-10-19T09:23:08.052Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-98638","references":[{"url":"https://git.kernel.org/stable/c/faf66e55e87498ab4bf88cdf9a629e61b3f2d3bc"},{"url":"https://git.kernel.org/stable/c/bae3e4493046de4fefa15f809d9b8dc114e84a3d"},{"url":"https://git.kernel.org/stable/c/2a2eb10795a1e495aebc7f829ccecb72c05b4fd9"}],"tags":["cve.org"],"ingestedAt":"2026-10-18T15:45:12.232Z","slug":"CVE-2026-98638","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nKVM: arm64: Validate the SVE vector length in pkvm_vcpu_init_sve()\n\npkvm_vcpu_init_sve() clamps only the upper bound of the host-provided\nsve_max_vl, so an invalid vector length reaches sve_state_size_from_vl()\nand the WARN_ON() there, which is fatal at EL2. The existing\n!sve_state_size test rejects such a length, but only after the macro has\nrun.\n\nCheck sve_vl_valid() before deriving the state size. A valid length\ncannot yield a zero size, so the !sve_state_size test goes with it.\n\n## Affected\n\n- `Linux >= 5db1bef933427aa467ad89c7b695a84a6b4afe16 < faf66e55e87498ab4bf88cdf9a629e61b3f2d3bc`\n- `Linux >= 5db1bef933427aa467ad89c7b695a84a6b4afe16 < bae3e4493046de4fefa15f809d9b8dc114e84a3d`\n- `Linux >= 5db1bef933427aa467ad89c7b695a84a6b4afe16 < 2a2eb10795a1e495aebc7f829ccecb72c05b4fd9`\n- `Linux 6.16`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}