{"id":"CVE-2026-89751","summary":"x86/tdx: Fix off-by-one in port I/O handling","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nx86/tdx: Fix off-by-one in port I/O handling\n\nhandle_in() and handle_out() in arch/x86/coco/tdx/tdx.c use:\n\n    u64 mask = GENMASK(BITS_PER_BYTE * size, 0);\n\nGENMASK(h, l) includes bit h. For size=1 (INB), this produces\nGENMASK(8, 0) = 0x1FF (9 bits) instead of GENMASK(7, 0) = 0xFF (8\nbits). The mask is one bit too wide for all I/O sizes.\n\nFix the mask calculation.","modified":"2026-09-12T11:47:16.940494944Z","published":"2026-09-11T19:46:55.314Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89751.json","cna_assigner":"Linux"},"references":[{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"},{"type":"WEB","url":"https://git.kernel.org/stable/c/0f63e656b1c679d32ac595de29d10c03efca6a25"},{"type":"WEB","url":"https://git.kernel.org/stable/c/222b7005e4519f633b4cd666226256abbab46a1a"},{"type":"WEB","url":"https://git.kernel.org/stable/c/bb45f705c4440dd3c689328319b88dd28770bbb8"},{"type":"WEB","url":"https://git.kernel.org/stable/c/c4a22154870813d10aa0b4c734a574c726f9d4b0"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89751.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89751"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"03149948832a078f759022ed5b92e722d8d23c26"},{"fixed":"222b7005e4519f633b4cd666226256abbab46a1a"},{"fixed":"c4a22154870813d10aa0b4c734a574c726f9d4b0"},{"fixed":"bb45f705c4440dd3c689328319b88dd28770bbb8"},{"fixed":"0f63e656b1c679d32ac595de29d10c03efca6a25"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-89751.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"5.19.0"},{"fixed":"6.12.109"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.50"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.2.4"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-89751.json"}}],"schema_version":"1.9.0"}