{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-64214", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-19T15:36:31.770Z", "datePublished": "2026-07-24T15:23:03.529Z", "dateUpdated": "2026-07-24T15:23:03.529Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-07-24T15:23:03.529Z" }, "descriptions": [ { "lang": "en", "value": "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": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "arch/powerpc/kernel/time.c" ], "versions": [ { "version": "cc15ff3275694fedc33cd3d53212a43eec7aa0bc", "lessThan": "51860e423592893cd7bfa7287d99a3aff4dc3a9d", "status": "affected", "versionType": "git" }, { "version": "cc15ff3275694fedc33cd3d53212a43eec7aa0bc", "lessThan": "a09d07ac45e283c9861a9ceea06f56d0ba851d22", "status": "affected", "versionType": "git" }, { "version": "cc15ff3275694fedc33cd3d53212a43eec7aa0bc", "lessThan": "72d8d1c36452a4d3ee134b1da48de7518c1329f9", "status": "affected", "versionType": "git" }, { "version": "cc15ff3275694fedc33cd3d53212a43eec7aa0bc", "lessThan": "6dcd072a5ae3aed336e4a67a7d4cc5205b240065", "status": "affected", "versionType": "git" }, { "version": "cc15ff3275694fedc33cd3d53212a43eec7aa0bc", "lessThan": "8079acc5ee5235a627e4586d4f42082a9000ea64", "status": "affected", "versionType": "git" }, { "version": "cc15ff3275694fedc33cd3d53212a43eec7aa0bc", "lessThan": "31467b23823ffec1f6fff407f8e3ca9af8b7491a", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "arch/powerpc/kernel/time.c" ], "versions": [ { "version": "5.18", "status": "affected" }, { "version": "0", "lessThan": "5.18", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.175", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.142", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.92", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.34", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.0.11", "lessThanOrEqual": "7.0.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1", "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": "5.18", "versionEndExcluding": "6.1.175" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.18", "versionEndExcluding": "6.6.142" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.18", "versionEndExcluding": "6.12.92" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.18", "versionEndExcluding": "6.18.34" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.18", "versionEndExcluding": "7.0.11" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.18", "versionEndExcluding": "7.1" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/51860e423592893cd7bfa7287d99a3aff4dc3a9d" }, { "url": "https://git.kernel.org/stable/c/a09d07ac45e283c9861a9ceea06f56d0ba851d22" }, { "url": "https://git.kernel.org/stable/c/72d8d1c36452a4d3ee134b1da48de7518c1329f9" }, { "url": "https://git.kernel.org/stable/c/6dcd072a5ae3aed336e4a67a7d4cc5205b240065" }, { "url": "https://git.kernel.org/stable/c/8079acc5ee5235a627e4586d4f42082a9000ea64" }, { "url": "https://git.kernel.org/stable/c/31467b23823ffec1f6fff407f8e3ca9af8b7491a" } ], "title": "powerpc/time: Remove redundant preempt_disable|enable() calls from arch_irq_work_raise()", "x_generator": { "engine": "bippy-1.2.0" } } } }