{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-31486", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-03-09T15:48:24.101Z", "datePublished": "2026-04-22T13:54:11.594Z", "dateUpdated": "2026-04-22T13:54:11.594Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-04-22T13:54:11.594Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nhwmon: (pmbus/core) Protect regulator operations with mutex\n\nThe regulator operations pmbus_regulator_get_voltage(),\npmbus_regulator_set_voltage(), and pmbus_regulator_list_voltage()\naccess PMBus registers and shared data but were not protected by\nthe update_lock mutex. This could lead to race conditions.\n\nHowever, adding mutex protection directly to these functions causes\na deadlock because pmbus_regulator_notify() (which calls\nregulator_notifier_call_chain()) is often called with the mutex\nalready held (e.g., from pmbus_fault_handler()). If a regulator\ncallback then calls one of the now-protected voltage functions,\nit will attempt to acquire the same mutex.\n\nRework pmbus_regulator_notify() to utilize a worker function to\nsend notifications outside of the mutex protection. Events are\nstored as atomics in a per-page bitmask and processed by the worker.\n\nInitialize the worker and its associated data during regulator\nregistration, and ensure it is cancelled on device removal using\ndevm_add_action_or_reset().\n\nWhile at it, remove the unnecessary include of linux/of.h."}], "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": "ddbb4db4ced1ba784fcd3500179a7291b6c5d7b7", "lessThan": "4e9d723d9f198b86f6882a84c501ba1f39e8d055", "status": "affected", "versionType": "git"}, {"version": "ddbb4db4ced1ba784fcd3500179a7291b6c5d7b7", "lessThan": "2c77ae315f3ce9d2c8e1609be74c9358c1fe4e07", "status": "affected", "versionType": "git"}, {"version": "ddbb4db4ced1ba784fcd3500179a7291b6c5d7b7", "lessThan": "754bd2b4a084b90b5e7b630e1f423061a9b9b761", "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": "3.19", "status": "affected"}, {"version": "0", "lessThan": "3.19", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.21", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.19.11", "lessThanOrEqual": "6.19.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.0", "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": "3.19", "versionEndExcluding": "6.18.21"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.19", "versionEndExcluding": "6.19.11"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.19", "versionEndExcluding": "7.0"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/4e9d723d9f198b86f6882a84c501ba1f39e8d055"}, {"url": "https://git.kernel.org/stable/c/2c77ae315f3ce9d2c8e1609be74c9358c1fe4e07"}, {"url": "https://git.kernel.org/stable/c/754bd2b4a084b90b5e7b630e1f423061a9b9b761"}], "title": "hwmon: (pmbus/core) Protect regulator operations with mutex", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nhwmon: (pmbus/core) Protect regulator operations with mutex\n\nThe regulator operations pmbus_regulator_get_voltage(),\npmbus_regulator_set_voltage(), and pmbus_regulator_list_voltage()\naccess PMBus registers and shared data but were not protected by\nthe update_lock mutex. This could lead to race conditions.\n\nHowever, adding mutex protection directly to these functions causes\na deadlock because pmbus_regulator_notify() (which calls\nregulator_notifier_call_chain()) is often called with the mutex\nalready held (e.g., from pmbus_fault_handler()). If a regulator\ncallback then calls one of the now-protected voltage functions,\nit will attempt to acquire the same mutex.\n\nRework pmbus_regulator_notify() to utilize a worker function to\nsend notifications outside of the mutex protection. Events are\nstored as atomics in a per-page bitmask and processed by the worker.\n\nInitialize the worker and its associated data during regulator\nregistration, and ensure it is cancelled on device removal using\ndevm_add_action_or_reset().\n\nWhile at it, remove the unnecessary include of linux/of.h."}], "id": "CVE-2026-31486", "lastModified": "2026-04-22T14:16:46.160", "metrics": {}, "published": "2026-04-22T14:16:46.160", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/2c77ae315f3ce9d2c8e1609be74c9358c1fe4e07"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/4e9d723d9f198b86f6882a84c501ba1f39e8d055"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/754bd2b4a084b90b5e7b630e1f423061a9b9b761"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[ddbb4db4ced1ba784fcd3500179a7291b6c5d7b7,4e9d723d9f198b86f6882a84c501ba1f39e8d055)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[ddbb4db4ced1ba784fcd3500179a7291b6c5d7b7,2c77ae315f3ce9d2c8e1609be74c9358c1fe4e07)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[ddbb4db4ced1ba784fcd3500179a7291b6c5d7b7,754bd2b4a084b90b5e7b630e1f423061a9b9b761)"}}], "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": "semver", "value": "3.19"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[0,3.19)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.18.21,6.19.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.19.11,6.20.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.0,*]"}}], "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"}], "analysis": {"en": {"generated_at": "2026-04-22T18:50:53.200044+00:00", "value": {"mitigation_remediation": ["Apply the kernel patch series referenced in the provided Git commit URLs that encrypt regulator operations with a mutex and rewires notification to a worker, thereby preventing race conditions and deadlocks.", "Reboot the system after applying the patch to load the updated kernel and clear any stale regulator state.", "If updating the kernel immediately is not possible, restrict access to PMBus regulator interfaces or disable the PMBus regulator driver to prevent concurrent operations until a patch is available."], "summary": {"action": "Assess Impact", "impact": "Race conditions in Linux kernel PMBus regulator operations"}, "threat_synthesis": {"affected_systems": "All Linux kernel variants that implement PMBus regulator drivers before the patch, affecting any hardware using PMBus power management hardware accessed by the kernel. The exact kernel versions are not listed but the vulnerability applies to any kernel containing the pre\u2011patch code.", "description_and_impact": "In the Linux kernel, regulator operations such as get, set, and list voltage for PMBus devices accessed shared registers and data without proper mutex protection, leading to race conditions. The patch adds a mutex lock but must avoid a deadlock caused by nested calls in the notifier chain. The vulnerability can result in inconsistent regulator state, potential hardware malfunction, and a possible denial\u2011of\u2011service scenario for devices relying on accurate voltage control.", "risk_and_exploitability": "The EPSS score is not available and the vulnerability is not listed in the CISA KEV catalog, indicating a lower profile of exploitation. The CVSS score is not published, but the lack of remote exploitation paths and requirement for kernel context suggest a moderate threat level. The likely attack vector would involve locally privileged code able to trigger concurrent regulator access, such as a malicious kernel module or a vulnerable user\u2011space interface that drives regulator functions. No known exploit has been reported."}}}}, "created": "2026-04-22T17:15:21.906269+00:00", "updated": "2026-04-22T19:00:08.090363+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"], "weaknesses": ["CWE-362"]}