{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-89442","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-09-11T19:38:34.703Z","datePublished":"2026-09-11T19:43:10.753Z","dateUpdated":"2026-09-14T11:59:52.425Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-09-14T11:59:52.425Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nplatform/x86: ISST: Validate socket ID in clos_assoc ioctl\n\nisst_if_clos_assoc() validates the user-supplied socket_id with\n'socket_id > topology_max_packages()', but isst_common.sst_inst[] is\nallocated with topology_max_packages() entries, so the valid index range\nis [0, topology_max_packages()).  The '>' comparison lets\nsocket_id == topology_max_packages() pass and index one entry past the\narray.\n\nIn addition, isst_common.sst_inst[socket_id] is NULL for an in-range\npackage that has no bound TPMI SST instance, and the pointer is used\nwithout a NULL check.  Both the out-of-bounds entry and the NULL pointer\nare then dereferenced by map_partition_power_domain_id() and the\nfollowing power_domain_info access.\n\nReject socket_id >= topology_max_packages() and a NULL sst_inst, matching\nthe checks already performed by get_instance()."}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - The bug is reached only through the ISST_IF_CLOS_ASSOC ioctl on /dev/isst_interface; isst_if_clos_assoc() is not invoked from network, Bluetooth, or USB processing.\nAC:L - The attacker sets punit_cpu_map=1 and socket_id equal to topology_max_packages() (one past sst_inst[]) or to an in-range unbound package (NULL sst_inst). Both are deterministic ioctl inputs with no race or victim state.\nPR:L - isst_if_open() has no capability check, and capable(CAP_SYS_ADMIN) runs only on the SET path after sst_inst is already indexed and dereferenced, so an unprivileged local user with the device fd can trigger it via GET.\nUI:N - The attacker issues the ioctl directly against /dev/isst_interface; no victim action such as mounting a filesystem or opening a file is required.\nS:U - The out-of-bounds pointer load and subsequent NULL or wild dereference stay in the kernel ISST driver and do not cross a VM, IOMMU, or sandbox boundary.\nC:H - socket_id == topology_max_packages() reads one pointer past sst_inst[] and treats it as struct tpmi_sst_struct; map_partition_power_domain_id() and readq() follow that object, and GET copy_to_user discloses the result as a kernel-memory read primitive.\nI:H - Treating the adjacent out-of-bounds pointer as sst_inst is type confusion; the confused object supplies sst_base used for writeq() on the SET path and further structure walks, which is an exploitable kernel write primitive.\nA:H - A NULL sst_inst or garbage out-of-bounds pointer is immediately dereferenced in map_partition_power_domain_id() and the following power_domain_info access, causing a kernel oops or panic."}]}],"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":"12a7d2cb811dd8a884dea088a2701fcb8d00136e","lessThan":"c847ea4851ecfa3462cc711ded2c3c3dd8d08ab8","status":"affected","versionType":"git"},{"version":"12a7d2cb811dd8a884dea088a2701fcb8d00136e","lessThan":"0d90ab5f80e19cddfeb0c9fab47a1f34aa932075","status":"affected","versionType":"git"},{"version":"12a7d2cb811dd8a884dea088a2701fcb8d00136e","lessThan":"82e707eff9e3b7ef6d96ecc23ea8876d20c7d6ca","status":"affected","versionType":"git"},{"version":"12a7d2cb811dd8a884dea088a2701fcb8d00136e","lessThan":"207b4dc6eb100141b122b2602504a1429a4b6558","status":"affected","versionType":"git"},{"version":"12a7d2cb811dd8a884dea088a2701fcb8d00136e","lessThan":"a89f07db0cb95c54dac4a8406c79a04e44a73c3c","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-rc1","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-rc1"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/c847ea4851ecfa3462cc711ded2c3c3dd8d08ab8"},{"url":"https://git.kernel.org/stable/c/0d90ab5f80e19cddfeb0c9fab47a1f34aa932075"},{"url":"https://git.kernel.org/stable/c/82e707eff9e3b7ef6d96ecc23ea8876d20c7d6ca"},{"url":"https://git.kernel.org/stable/c/207b4dc6eb100141b122b2602504a1429a4b6558"},{"url":"https://git.kernel.org/stable/c/a89f07db0cb95c54dac4a8406c79a04e44a73c3c"}],"title":"platform/x86: ISST: Validate socket ID in clos_assoc ioctl","x_generator":{"engine":"bippy-1.2.0"}}}}