{"id":"CVE-2026-99017","published":"2026-10-23T13:17:24.530","lastModified":"2026-10-24T14:16:52.790","description":"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.","cvssScore":7,"cvssSeverity":"HIGH","cvssVector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H","cwes":[],"vendors":[],"products":[],"references":[{"url":"https://git.kernel.org/stable/c/298510bbc7c3017c0faf481c6ea66f1065b657b4","tags":[]},{"url":"https://git.kernel.org/stable/c/7fee577a2fa78b9a76da015beec1ccf978746ebb","tags":[]},{"url":"https://git.kernel.org/stable/c/fa465a7819ecbe5801b78c088d3cadaf2664b8ca","tags":[]}],"exploitRefs":[],"hasPoc":false,"ai":null}