{"id":"CVE-2026-99017","summary":"riscv: errata: select RISCV_ALTERNATIVE_EARLY for THEAD GHOSTWRITE","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nriscv: errata: select RISCV_ALTERNATIVE_EARLY for THEAD GHOSTWRITE\n\nerrata_probe_ghostwrite() only marks the CPU as vulnerable when it is\ncalled at the RISCV_ALTERNATIVES_EARLY_BOOT stage, and the mitigation\nin ghostwrite_enable_mitigation() only takes effect if the vulnerable\nstate was recorded before the boot alternatives are patched.\n\nThe early boot stage is only executed when CONFIG_RISCV_ALTERNATIVE_EARLY\nis enabled, which currently is only selected by ERRATA_THEAD_MAE. In a\nkernel built with ERRATA_THEAD_GHOSTWRITE=y but ERRATA_THEAD_MAE=n, the\nearly alternatives never run, so ghostwrite_state is never set to\nVULNERABLE: ghostwrite_enable_mitigation() returns false, xtheadvector\nremains enabled, and sysfs reports \"Not affected\" on a vulnerable\nT-Head C9xx CPU.\n\nSelect RISCV_ALTERNATIVE_EARLY from ERRATA_THEAD_GHOSTWRITE so that the\nvulnerability is detected in the early boot stage and the default\nmitigation is applied.","modified":"2026-10-26T02:31:55.638677746Z","published":"2026-10-23T12:20:53.518Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/99xxx/CVE-2026-99017.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/298510bbc7c3017c0faf481c6ea66f1065b657b4"},{"type":"WEB","url":"https://git.kernel.org/stable/c/7fee577a2fa78b9a76da015beec1ccf978746ebb"},{"type":"WEB","url":"https://git.kernel.org/stable/c/fa465a7819ecbe5801b78c088d3cadaf2664b8ca"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/99xxx/CVE-2026-99017.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-99017"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"4bf97069239bcfca9840936313c7ac35a6e04488"},{"fixed":"fa465a7819ecbe5801b78c088d3cadaf2664b8ca"},{"fixed":"7fee577a2fa78b9a76da015beec1ccf978746ebb"},{"fixed":"298510bbc7c3017c0faf481c6ea66f1065b657b4"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-99017.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"6.14.0"},{"fixed":"6.18.57"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.2.11"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-99017.json"}}],"schema_version":"1.9.2","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H"}]}