{ "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" } } } }