{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-74711", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-15T05:44:03.928Z", "datePublished": "2026-08-22T15:33:07.779Z", "dateUpdated": "2026-10-21T12:46:12.854Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-21T12:46:12.854Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nhwmon: (pmbus) Fix type confusion in notification logic\n\nSashiko reports:\n\nAt the start of the loop in pmbus_notify(), the code unconditionally casts\nevery attribute to a struct sensor_device_attribute:\n\ndrivers/hwmon/pmbus/pmbus_core.c:pmbus_notify() {\n for (i = 0; i < data->num_attributes; i++) {\n struct device_attribute *da = to_dev_attr(data->group.attrs[i]);\n struct sensor_device_attribute *attr = to_sensor_dev_attr(da);\n int index = attr->index;\n...\n}\n\nHowever, data->group.attrs can contain other types like struct\npmbus_samples_reg or struct pmbus_sensor, which only embed a base\nstruct device_attribute.\n\nIf da is a struct pmbus_samples_reg, dev_attr is the last member. Casting\nit to struct sensor_device_attribute and reading the index field appears\nto access memory past the end of the allocation, which might trigger a\nslab-out-of-bounds read.\n\nAdditionally, if da is a struct pmbus_sensor, casting it causes the index\nfield to overlap with the page, phase, and reg fields. Could this produce\na garbage mask on little-endian systems that spuriously matches the target\nreg, page, and flags during an alert?\n\nFix the problem by using struct sensor_device_attr in struct pmbus_sensor\nand struct pmbus_label. Since those attributes never trigger a\nnotification, set the value of attr->index to -1 for them. Use this value\nto distinguish from boolean attributes which _can_ trigger a notification\nand use the index field to encode mask, page, and register values." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "baseScore": 8.4, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The flawed pmbus_notify() runs only in the PMBus SMBALERT threaded IRQ handler after the host kernel reads fault status from an on-board I2C/SMBus PSU/PMIC; reaching it requires local presence on a system exposing that bus, not a remote network protocol.\nAC:L - Once SMBALERT IRQ handling is enabled, the type confusion and slab out-of-bounds read occur deterministically on every alert while iterating attributes; an attacker can repeatedly provoke PSU/PMIC faults (e.g., sustained CPU/GPU load) rather than depend on uncontrollable timing.\nPR:N - No special kernel capability is needed to hit the IRQ path—any unprivileged local process that can drive hardware into an overcurrent/overtemp fault (cloud tenant, factory HMI user, embedded service account) can cause SMBALERT and exercise the bug.\nUI:N - Exploitation is driven by attacker-induced or naturally occurring PMBus fault interrupts and does not require any victim to open files, click prompts, or perform other interactive actions.\nS:U - Impact is confined to kernel memory safety within the host OS security authority; it is not a VM escape, IOMMU/DMA boundary bypass, or other cross-authority compromise.\nC:H - Casting pmbus_samples_reg device attributes to sensor_device_attribute reads attr->index past the object end (slab out-of-bounds), and pmbus_sensor casts reinterpret adjacent page/phase/reg bytes as an index, enabling kernel heap metadata or pointer disclosure.\nI:H - This is a type confusion in kernel notification logic: mis-decoded indices can spuriously satisfy reg/page/mask checks and drive sysfs_notify/uevent on unintended attributes, a memory-safety defect with potential for further corruption primitives.\nA:H - The out-of-bounds slab read and malformed attribute matching in interrupt context can trigger KASAN/BUG faults or kernel oops/panic when alerts fire on production systems with PMBus SMBALERT wired." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/hwmon/pmbus/pmbus_core.c" ], "versions": [ { "version": "f469bde9afd136598a0c4edc054296e6046f90ee", "lessThan": "ce443f6827b97e03a0fb34ebfddc8939c85e0500", "status": "affected", "versionType": "git" }, { "version": "f469bde9afd136598a0c4edc054296e6046f90ee", "lessThan": "1c8dd39d48494cceb2c27c1911cbf26d10ce8514", "status": "affected", "versionType": "git" }, { "version": "f469bde9afd136598a0c4edc054296e6046f90ee", "lessThan": "821f6416e69782fa662aff94b5ea52c943042790", "status": "affected", "versionType": "git" }, { "version": "f469bde9afd136598a0c4edc054296e6046f90ee", "lessThan": "0b121de89a99c54bcf516999b04e8531c84f08d5", "status": "affected", "versionType": "git" }, { "version": "f469bde9afd136598a0c4edc054296e6046f90ee", "lessThan": "59bd68ab05a8f9c9a60b6ec44682084184803ff4", "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/hwmon/pmbus/pmbus_core.c" ], "versions": [ { "version": "6.4", "status": "affected" }, { "version": "0", "lessThan": "6.4", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.160", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.114", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.45", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.9", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2", "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": "6.6.160" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.4", "versionEndExcluding": "6.12.114" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.4", "versionEndExcluding": "6.18.45" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.4", "versionEndExcluding": "7.1.9" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.4", "versionEndExcluding": "7.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/ce443f6827b97e03a0fb34ebfddc8939c85e0500" }, { "url": "https://git.kernel.org/stable/c/1c8dd39d48494cceb2c27c1911cbf26d10ce8514" }, { "url": "https://git.kernel.org/stable/c/821f6416e69782fa662aff94b5ea52c943042790" }, { "url": "https://git.kernel.org/stable/c/0b121de89a99c54bcf516999b04e8531c84f08d5" }, { "url": "https://git.kernel.org/stable/c/59bd68ab05a8f9c9a60b6ec44682084184803ff4" } ], "title": "hwmon: (pmbus) Fix type confusion in notification logic", "x_generator": { "engine": "bippy-1.2.0" } } } }