{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-72395", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-09T03:40:39.924Z", "datePublished": "2026-08-15T05:56:22.400Z", "dateUpdated": "2026-08-17T05:43:38.599Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-17T05:43:38.599Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nhwmon: (pmbus) Fix passing events to regulator core\n\nSashiko reports:\n\nCommit 754bd2b4a084 (\"hwmon: (pmbus/core) Protect regulator operations with\nmutex\") introduced a worker to batch regulator events over time using\natomic_or(). The delayed worker then passes the combined bitmask unmodified\nto regulator_notifier_call_chain().\n\nThe core regulator subsystem's regulator_handle_critical() function\nevaluates the event parameter using a strict switch statement. If\nmultiple distinct faults occur before the worker runs (e.g.,\nREGULATOR_EVENT_UNDER_VOLTAGE | REGULATOR_EVENT_OVER_CURRENT), the combined\nbitmask fails to match any case. This leaves the reason as NULL and\ncompletely bypasses the critical hw_protection_trigger().\n\nFix the problem by passing events bit by bit to the regulator event\nhandler." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H", "baseScore": 7.1, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The flaw is only reachable through the PMBus SMBALERT threaded IRQ handler (pmbus_fault_handler) that reads hardware fault status over I2C; there is no network, adjacent-radio, or direct physical-device API path, but local actors on PMBus-equipped servers, routers, and embedded boards can induce multi-fault conditions.\nAC:L - _pmbus_get_flags() ORs multiple REGULATOR_EVENT_* bits from a single STATUS read, and pmbus_regulator_notify() further batches concurrent IRQs via atomic_or() before the worker runs, so combined masks like UNDER_VOLTAGE|OVER_CURRENT are produced deterministically without races or layout dependencies the attacker cannot influence.\nPR:L - Triggering the IRQ requires causing real PMBus regulator fault bits (e.g., over-current plus under-voltage during supply stress), which an unprivileged local user can induce through heavy workload and power instability on affected platforms; CAP_NET_ADMIN/user-namespace tricks are not needed and no init-namespace root capability is required.\nUI:N - Once fault conditions are present the SMBALERT IRQ and workqueue fire automatically through pmbus_fault_handler and pmbus_regulator_notify_worker; no separate victim action such as mounting media, plugging hardware, or approving a prompt is required.\nS:U - The impact is bypassing kernel hw_protection_trigger() orderly shutdown/reboot for system-critical PMBus regulators on the same host; it does not cross VM, IOMMU, or sandbox security boundaries and is not a guest-to-host escape.\nC:N - This is a notifier bit-mask logic error that leaves regulator_handle_critical() with a NULL reason; there is no kernel memory corruption, use-after-free, or out-of-bounds access that could disclose pointers or arbitrary memory.\nI:H - When multiple distinct fault events are combined, hw_protection_trigger() is completely skipped for system-critical regulators, defeating the kernel's mandatory emergency shutdown policy and allowing continued operation under simultaneous critical under-voltage/over-current/fail conditions that can corrupt power hardware.\nA:H - Bypassing hw_protection_trigger() during simultaneous critical PMBus regulator faults prevents the intended emergency orderly_poweroff/reboot, leaving telecom, data-center, and embedded systems running under dangerous rail conditions that can cause hardware failure, forced resets, and sustained denial of service." } ] } ], "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": "b26849cffaa7c43355b82e9bef3725e786973a1a", "lessThan": "2106bf4056858fcce3624e0c51f6fee4d41d3f2f", "status": "affected", "versionType": "git" }, { "version": "acf04e2863132f6d9222f71f3a76fb9782cbe061", "lessThan": "48fe43666950efefb7ac5fbdc012c1b3604096bf", "status": "affected", "versionType": "git" }, { "version": "4e9d723d9f198b86f6882a84c501ba1f39e8d055", "lessThan": "489291b6b56978cc50d34e8e13f9636ea296ba8a", "status": "affected", "versionType": "git" }, { "version": "754bd2b4a084b90b5e7b630e1f423061a9b9b761", "lessThan": "b0ff6b6ae9c5183ef701ece7016698bde5a5bfba", "status": "affected", "versionType": "git" }, { "version": "754bd2b4a084b90b5e7b630e1f423061a9b9b761", "lessThan": "9ef7dacd44216bf5ea05c8aef49eba4d145f4047", "status": "affected", "versionType": "git" }, { "version": "2c77ae315f3ce9d2c8e1609be74c9358c1fe4e07", "status": "affected", "versionType": "git" }, { "version": "6.6.143", "lessThan": "6.6.145", "status": "affected", "versionType": "semver" }, { "version": "6.12.92", "lessThan": "6.12.97", "status": "affected", "versionType": "semver" }, { "version": "6.18.21", "lessThan": "6.18.40", "status": "affected", "versionType": "semver" }, { "version": "6.19.11", "lessThan": "6.20", "status": "affected", "versionType": "semver" } ] }, { "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": "7.0", "status": "affected" }, { "version": "0", "lessThan": "7.0", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.145", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.97", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.40", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.5", "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": "6.6.143", "versionEndExcluding": "6.6.145" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.12.92", "versionEndExcluding": "6.12.97" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.18.21", "versionEndExcluding": "6.18.40" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "7.0", "versionEndExcluding": "7.1.5" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "7.0", "versionEndExcluding": "7.2" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.19.11" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/2106bf4056858fcce3624e0c51f6fee4d41d3f2f" }, { "url": "https://git.kernel.org/stable/c/48fe43666950efefb7ac5fbdc012c1b3604096bf" }, { "url": "https://git.kernel.org/stable/c/489291b6b56978cc50d34e8e13f9636ea296ba8a" }, { "url": "https://git.kernel.org/stable/c/b0ff6b6ae9c5183ef701ece7016698bde5a5bfba" }, { "url": "https://git.kernel.org/stable/c/9ef7dacd44216bf5ea05c8aef49eba4d145f4047" } ], "title": "hwmon: (pmbus) Fix passing events to regulator core", "x_generator": { "engine": "bippy-1.2.0" } } } }