{ "schemaVersion": 1, "attribution": [ { "source": "CISA Known Exploited Vulnerabilities", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog", "licence": "US government work" }, { "source": "GitHub Advisory Database", "url": "https://github.com/advisories", "licence": "CC BY 4.0" }, { "source": "Have I Been Pwned", "url": "https://haveibeenpwned.com/", "licence": "CC BY 4.0" }, { "source": "CVE Program (CVE records)", "url": "https://www.cve.org/Legal/TermsOfUse", "licence": "CVE Terms of Use", "notice": "Copyright © 1999-2026, The MITRE Corporation. CVE is a trademark and the CVE logo is a registered trademark of The MITRE Corporation.", "terms": "CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE™). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy." }, { "source": "FIRST EPSS", "url": "https://www.first.org/epss/", "licence": "free to use; FIRST requests attribution" } ], "record": { "id": "CVE-2026-64214", "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2026-64214", "idYear": 2026, "status": "PUBLISHED", "publishedAt": "2026-07-24T15:23:03.529Z", "updatedAt": "2026-07-24T15:23:03.529Z", "importedAt": "2026-10-24T01:58:25.636Z", "snapshot": { "id": "cve_2026-10-24_midnight_baseline", "at": "2026-10-24T00:00:00.000Z", "source": "https://github.com/CVEProject/cvelistV5/releases/tag/cve_2026-10-24_0100Z" }, "facts": { "title": "powerpc/time: Remove redundant preempt_disable|enable() calls from arch_irq_work_raise()", "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\npowerpc/time: Remove redundant preempt_disable|enable() calls from arch_irq_work_raise()\n\nA kernel panic is observed when handling machine check exceptions from\nreal mode.\n\n BUG: Unable to handle kernel data access on read at 0xc00000006be21300\n Oops: Kernel access of bad area, sig: 11 [#1]\n MSR: 8000000000001003 CR: 88222248 XER: 00000005\n CFAR: c00000000003ffc4 DAR: c00000006be21300 DSISR: 40000000 IRQMASK: 0\n NIP [c000000000029e40] arch_irq_work_raise+0x10/0x70\n LR [c00000000003ffc8] machine_check_queue_event+0xa8/0x150\n Call Trace:\n [c0000000179d3c70] [c00000000003ff64] machine_check_queue_event+0x44/0x150\n [c0000000179d3d30] [c0000000000084e0] machine_check_early_common+0x1f0/0x2c0\n\nThe crash occurs because arch_irq_work_raise() calls preempt_disable()\nfrom machine check exception (MCE) handlers running in real mode. In\nthis context, accessing the preempt_count can fault, leading to the panic.\n\nThe preempt_disable()/preempt_enable() pair in arch_irq_work_raise()\nwas originally added by commit 0fe1ac48bef0 (\"powerpc/perf_event: Fix\noops due to perf_event_do_pending call\") to avoid races while raising\nirq work from exception context.\n\nLater, commit 471ba0e686cb (\"irq_work: Do not raise an IPI when\nqueueing work on the local CPU\") added preemption protection in\nirq_work_queue() path, while commit 20b876918c06 (\"irq_work: Use per\ncpu atomics instead of regular atomics\") added equivalent\nprotection in irq_work_queue_on() before reaching arch_irq_work_raise():\n\n irq_work_queue() / irq_work_queue_on()\n -> preempt_disable()\n -> __irq_work_queue_local()\n -> irq_work_raise()\n -> arch_irq_work_raise()\n\nAs a result, callers other than mce_irq_work_raise() already execute\nwith preemption disabled, making the additional\npreempt_disable()/preempt_enable() pair in arch_irq_work_raise()\nredundant.\n\nThe arch_irq_work_raise() function executes in NMI context when called\nfrom MCE handler. Hence we will not be preempted or scheduled out since\nwe are in NMI context with MSR[EE]=0. Therefore, it is safe to remove\nthe preempt_disable()/preempt_enable() calls from here.\n\nRemove it to avoid accessing preempt_count from real mode context.\n\n[Maddy: Fixed the commit title]", "affected": [ { "vendor": "Linux", "product": "Linux", "defaultStatus": "unaffected", "versions": [ { "version": "cc15ff3275694fedc33cd3d53212a43eec7aa0bc", "status": "affected", "versionType": "git", "lessThan": "51860e423592893cd7bfa7287d99a3aff4dc3a9d" }, { "version": "cc15ff3275694fedc33cd3d53212a43eec7aa0bc", "status": "affected", "versionType": "git", "lessThan": "a09d07ac45e283c9861a9ceea06f56d0ba851d22" }, { "version": "cc15ff3275694fedc33cd3d53212a43eec7aa0bc", "status": "affected", "versionType": "git", "lessThan": "72d8d1c36452a4d3ee134b1da48de7518c1329f9" }, { "version": "cc15ff3275694fedc33cd3d53212a43eec7aa0bc", "status": "affected", "versionType": "git", "lessThan": "6dcd072a5ae3aed336e4a67a7d4cc5205b240065" }, { "version": "cc15ff3275694fedc33cd3d53212a43eec7aa0bc", "status": "affected", "versionType": "git", "lessThan": "8079acc5ee5235a627e4586d4f42082a9000ea64" }, { "version": "cc15ff3275694fedc33cd3d53212a43eec7aa0bc", "status": "affected", "versionType": "git", "lessThan": "31467b23823ffec1f6fff407f8e3ca9af8b7491a" } ] }, { "vendor": "Linux", "product": "Linux", "defaultStatus": "affected", "versions": [ { "version": "5.18", "status": "affected" }, { "version": "0", "status": "unaffected", "versionType": "semver", "lessThan": "5.18" }, { "version": "6.1.175", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.1.*" }, { "version": "6.6.142", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.6.*" }, { "version": "6.12.92", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.12.*" }, { "version": "6.18.34", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.18.*" }, { "version": "7.0.11", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "7.0.*" }, { "version": "7.1", "status": "unaffected", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*" } ] } ] } } }