CVE-2026-89443

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-89443", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.704Z", "datePublished": "2026-09-11T19:43:11.407Z", "dateUpdated": "2026-10-19T08:46:52.766Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T08:46:52.766Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nplatform/x86: ISST: Validate level in perf mask ioctls\n\nisst_if_get_perf_level_mask() and isst_if_get_base_freq_mask() use the\nuser-provided level as an index into perf_levels[] via\n_read_pp_level_info() and _read_bf_level_info(), but neither helper\nvalidates it first.\n\nThe adjacent level-info helpers reject levels above max_level before\nreading the same per-level register block. Add the same bounds checks to\nthe mask helpers, and reject disabled SST-PP levels in\nisst_if_get_perf_level_mask() to match isst_if_get_perf_level_info().\n\nThis prevents out-of-bounds reads from the per-level offset table on\ninvalid ioctl input."}], "metrics": [{"cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H", "baseScore": 7.1, "baseSeverity": "HIGH"}, "scenarios": [{"lang": "en", "value": "AV:L - The bug is reached only via local ioctl(ISST_IF_GET_PERF_LEVEL_CPU_MASK or ISST_IF_GET_BASE_FREQ_CPU_MASK) on /dev/isst_interface, dispatched through isst_if_def_ioctl() to the TPMI SST helpers; there is no network, Bluetooth, or physical-device path into these functions.\nAC:L - The attacker fully controls the ioctl argument, including the 8-bit level used as perf_levels[level] with no pre-fix bounds check; the out-of-bounds table read and following MMIO readq() occur deterministically, with no race or attacker-uncontrollable memory layout required.\nPR:L - isst_if_open() and both GET mask ioctls perform no capable() check; CAP_SYS_ADMIN is required only for SST write/set commands, so a local process that can open /dev/isst_interface can reach this read path without init-namespace admin capabilities.\nUI:N - The attacker opens /dev/isst_interface and issues the crafted ioctl from their own process; no separate victim action such as mounting a filesystem or opening a file is required.\nS:U - The out-of-bounds kernel/MMIO read and any resulting oops stay within the host kernel security authority; this is not a VM escape, IOMMU bypass, or other cross-boundary impact.\nC:H - User-supplied level (0-255) indexes perf_levels[] (at most 8 entries), reading adjacent heap as a signed mmio_offset that is then used in readq(); the 64-bit result is copied to userspace when punit_cpu_map is set, an out-of-bounds read rated High unless strictly a few bytes.\nI:N - Both helpers only issue MMIO readq() and copy_to_user of the resulting mask; there is no writeq, heap write, type confusion, or control-flow hijack primitive on this path.\nA:H - sst_base is a bounded ioremap from devm_ioremap_resource(); a heap-derived mmio_offset can drive readq() outside that mapping and oops, and the perf_levels[] over-read itself can fault on hardened kernels; any kernel crash is High availability impact."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["drivers/platform/x86/intel/speed_select_if/isst_tpmi_core.c"], "versions": [{"version": "ea009e4769fa3bd05d4c111c3b6865eb3a9be829", "lessThan": "beb22ebf76c0415f22d2d0c3f1ff0627e7ae4a68", "status": "affected", "versionType": "git"}, {"version": "ea009e4769fa3bd05d4c111c3b6865eb3a9be829", "lessThan": "1a8bab5ceee1a42a78de12d3d69f67516a20588e", "status": "affected", "versionType": "git"}, {"version": "ea009e4769fa3bd05d4c111c3b6865eb3a9be829", "lessThan": "1889a9156553f0692acd57caf15e877baace1a01", "status": "affected", "versionType": "git"}, {"version": "ea009e4769fa3bd05d4c111c3b6865eb3a9be829", "lessThan": "d19385624bdfb577db9c94bb8879992fd5e17bcd", "status": "affected", "versionType": "git"}, {"version": "ea009e4769fa3bd05d4c111c3b6865eb3a9be829", "lessThan": "80e0d353c86a9a168ad6d213f494796294381538", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["drivers/platform/x86/intel/speed_select_if/isst_tpmi_core.c"], "versions": [{"version": "6.4", "status": "affected"}, {"version": "0", "lessThan": "6.4", "status": "unaffected", "versionType": "semver"}, {"version": "6.6.157", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.109", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.50", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.2.4", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.3", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix"}]}], "cpeApplicability": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.4", "versionEndExcluding": "6.6.157"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.4", "versionEndExcluding": "6.12.109"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.4", "versionEndExcluding": "6.18.50"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.4", "versionEndExcluding": "7.2.4"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.4", "versionEndExcluding": "7.3"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/beb22ebf76c0415f22d2d0c3f1ff0627e7ae4a68"}, {"url": "https://git.kernel.org/stable/c/1a8bab5ceee1a42a78de12d3d69f67516a20588e"}, {"url": "https://git.kernel.org/stable/c/1889a9156553f0692acd57caf15e877baace1a01"}, {"url": "https://git.kernel.org/stable/c/d19385624bdfb577db9c94bb8879992fd5e17bcd"}, {"url": "https://git.kernel.org/stable/c/80e0d353c86a9a168ad6d213f494796294381538"}], "title": "platform/x86: ISST: Validate level in perf mask ioctls", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["drivers/platform/x86/intel/speed_select_if/isst_tpmi_core.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "beb22ebf76c0415f22d2d0c3f1ff0627e7ae4a68", "status": "affected", "version": "ea009e4769fa3bd05d4c111c3b6865eb3a9be829", "versionType": "git"}, {"lessThan": "1a8bab5ceee1a42a78de12d3d69f67516a20588e", "status": "affected", "version": "ea009e4769fa3bd05d4c111c3b6865eb3a9be829", "versionType": "git"}, {"lessThan": "1889a9156553f0692acd57caf15e877baace1a01", "status": "affected", "version": "ea009e4769fa3bd05d4c111c3b6865eb3a9be829", "versionType": "git"}, {"lessThan": "d19385624bdfb577db9c94bb8879992fd5e17bcd", "status": "affected", "version": "ea009e4769fa3bd05d4c111c3b6865eb3a9be829", "versionType": "git"}, {"lessThan": "80e0d353c86a9a168ad6d213f494796294381538", "status": "affected", "version": "ea009e4769fa3bd05d4c111c3b6865eb3a9be829", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["drivers/platform/x86/intel/speed_select_if/isst_tpmi_core.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "6.4"}, {"lessThan": "6.4", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.6.*", "status": "unaffected", "version": "6.6.157", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.109", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.50", "versionType": "semver"}, {"lessThanOrEqual": "7.2.*", "status": "unaffected", "version": "7.2.4", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.3", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nplatform/x86: ISST: Validate level in perf mask ioctls\n\nisst_if_get_perf_level_mask() and isst_if_get_base_freq_mask() use the\nuser-provided level as an index into perf_levels[] via\n_read_pp_level_info() and _read_bf_level_info(), but neither helper\nvalidates it first.\n\nThe adjacent level-info helpers reject levels above max_level before\nreading the same per-level register block. Add the same bounds checks to\nthe mask helpers, and reject disabled SST-PP levels in\nisst_if_get_perf_level_mask() to match isst_if_get_perf_level_info().\n\nThis prevents out-of-bounds reads from the per-level offset table on\ninvalid ioctl input."}], "id": "CVE-2026-89443", "lastModified": "2026-10-19T09:17:36.333", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 7.1, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "NONE", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H", "version": "3.1"}, "exploitabilityScore": 1.8, "impactScore": 5.2, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}]}, "published": "2026-09-11T20:19:24.737", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/1889a9156553f0692acd57caf15e877baace1a01"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/1a8bab5ceee1a42a78de12d3d69f67516a20588e"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/80e0d353c86a9a168ad6d213f494796294381538"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/beb22ebf76c0415f22d2d0c3f1ff0627e7ae4a68"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/d19385624bdfb577db9c94bb8879992fd5e17bcd"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{"bugzilla": {"description": "kernel: Linux kernel: ISST module out-of-bounds read via invalid input", "id": "2532417", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2532417"}, "csaw": false, "cvss3": {"cvss3_base_score": "4.4", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:L", "status": "draft"}, "cwe": "CWE-125", "details": ["A flaw was found in the Linux kernel's platform/x86 ISST module. The `isst_if_get_perf_level_mask()` and `isst_if_get_base_freq_mask()` functions fail to validate a user-provided 'level' parameter. A local attacker could exploit this by providing an invalid 'level' value, leading to an out-of-bounds read from the per-level offset table. This could result in information disclosure or a denial of service (DoS)."], "name": "CVE-2026-89443", "public_date": "2026-09-11T19:43:11Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-89443\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-89443\nhttps://git.kernel.org/stable/c/1889a9156553f0692acd57caf15e877baace1a01\nhttps://git.kernel.org/stable/c/1a8bab5ceee1a42a78de12d3d69f67516a20588e\nhttps://git.kernel.org/stable/c/80e0d353c86a9a168ad6d213f494796294381538\nhttps://git.kernel.org/stable/c/d19385624bdfb577db9c94bb8879992fd5e17bcd"], "threat_severity": "Moderate"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[ea009e4769fa3bd05d4c111c3b6865eb3a9be829,1a8bab5ceee1a42a78de12d3d69f67516a20588e)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[ea009e4769fa3bd05d4c111c3b6865eb3a9be829,1889a9156553f0692acd57caf15e877baace1a01)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[ea009e4769fa3bd05d4c111c3b6865eb3a9be829,d19385624bdfb577db9c94bb8879992fd5e17bcd)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[ea009e4769fa3bd05d4c111c3b6865eb3a9be829,80e0d353c86a9a168ad6d213f494796294381538)"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "6.4"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[0,6.4)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.12.109,7.0.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.18.50,7.0.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.2.4,8.0.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.3-rc1,*]"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}], "created": "2026-09-12T22:00:07.577252+00:00", "title": "Linux Kernel: Out\u2011of\u2011Bounds Read in ISST Driver Perf Mask IOCTL", "updated": "2026-09-21T01:45:07.957501+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"]}