{"id":"CVE-2026-89751","state":"PUBLISHED","title":"x86/tdx: Fix off-by-one in port I/O handling","description":"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.","publishedAt":"2026-09-11T19:46:55.314Z","updatedAt":"2026-10-19T08:52:05.025Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"03149948832a078f759022ed5b92e722d8d23c26","status":"affected","lessThan":"c6875423ad849ac234ab9812eb72f37ff8a490b4","versionType":"git"},{"version":"03149948832a078f759022ed5b92e722d8d23c26","status":"affected","lessThan":"220011fe95fc78b2bc2d7d43893bc73957a5c811","versionType":"git"},{"version":"03149948832a078f759022ed5b92e722d8d23c26","status":"affected","lessThan":"222b7005e4519f633b4cd666226256abbab46a1a","versionType":"git"},{"version":"03149948832a078f759022ed5b92e722d8d23c26","status":"affected","lessThan":"c4a22154870813d10aa0b4c734a574c726f9d4b0","versionType":"git"},{"version":"03149948832a078f759022ed5b92e722d8d23c26","status":"affected","lessThan":"bb45f705c4440dd3c689328319b88dd28770bbb8","versionType":"git"},{"version":"03149948832a078f759022ed5b92e722d8d23c26","status":"affected","lessThan":"0f63e656b1c679d32ac595de29d10c03efca6a25","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["arch/x86/coco/tdx/tdx.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.19","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.19","versionType":"semver"},{"version":"6.1.188","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.157","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.109","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.50","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.4","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["arch/x86/coco/tdx/tdx.c"]}],"references":["https://git.kernel.org/stable/c/c6875423ad849ac234ab9812eb72f37ff8a490b4","https://git.kernel.org/stable/c/220011fe95fc78b2bc2d7d43893bc73957a5c811","https://git.kernel.org/stable/c/222b7005e4519f633b4cd666226256abbab46a1a","https://git.kernel.org/stable/c/c4a22154870813d10aa0b4c734a574c726f9d4b0","https://git.kernel.org/stable/c/bb45f705c4440dd3c689328319b88dd28770bbb8","https://git.kernel.org/stable/c/0f63e656b1c679d32ac595de29d10c03efca6a25"],"weaknesses":[],"ingestedAt":"2026-10-29T20:13:26.108Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/89xxx/CVE-2026-89751.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-89751","state":"PUBLISHED","datePublished":"2026-09-11T19:46:55.314Z","dateUpdated":"2026-10-19T08:52:05.025Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-11T19:38:34.762Z"},"containers":{"cna":{"title":"x86/tdx: Fix off-by-one in port I/O handling","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"03149948832a078f759022ed5b92e722d8d23c26","status":"affected","lessThan":"c6875423ad849ac234ab9812eb72f37ff8a490b4","versionType":"git"},{"version":"03149948832a078f759022ed5b92e722d8d23c26","status":"affected","lessThan":"220011fe95fc78b2bc2d7d43893bc73957a5c811","versionType":"git"},{"version":"03149948832a078f759022ed5b92e722d8d23c26","status":"affected","lessThan":"222b7005e4519f633b4cd666226256abbab46a1a","versionType":"git"},{"version":"03149948832a078f759022ed5b92e722d8d23c26","status":"affected","lessThan":"c4a22154870813d10aa0b4c734a574c726f9d4b0","versionType":"git"},{"version":"03149948832a078f759022ed5b92e722d8d23c26","status":"affected","lessThan":"bb45f705c4440dd3c689328319b88dd28770bbb8","versionType":"git"},{"version":"03149948832a078f759022ed5b92e722d8d23c26","status":"affected","lessThan":"0f63e656b1c679d32ac595de29d10c03efca6a25","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["arch/x86/coco/tdx/tdx.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.19","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.19","versionType":"semver"},{"version":"6.1.188","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.157","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.109","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.50","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.4","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["arch/x86/coco/tdx/tdx.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/c6875423ad849ac234ab9812eb72f37ff8a490b4"},{"url":"https://git.kernel.org/stable/c/220011fe95fc78b2bc2d7d43893bc73957a5c811"},{"url":"https://git.kernel.org/stable/c/222b7005e4519f633b4cd666226256abbab46a1a"},{"url":"https://git.kernel.org/stable/c/c4a22154870813d10aa0b4c734a574c726f9d4b0"},{"url":"https://git.kernel.org/stable/c/bb45f705c4440dd3c689328319b88dd28770bbb8"},{"url":"https://git.kernel.org/stable/c/0f63e656b1c679d32ac595de29d10c03efca6a25"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-19T08:52:05.025Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.19","versionEndExcluding":"6.1.188"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.19","versionEndExcluding":"6.6.157"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.19","versionEndExcluding":"6.12.109"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.19","versionEndExcluding":"6.18.50"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.19","versionEndExcluding":"7.2.4"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.19","versionEndExcluding":"7.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}