CVE-2026-64214
powerpc/time: Remove redundant preempt_disable|enable() calls from arch_irq_work_raise()
Description
In the Linux kernel, the following vulnerability has been resolved: powerpc/time: Remove redundant preempt_disable|enable() calls from arch_irq_work_raise() A kernel panic is observed when handling machine check exceptions from real mode. BUG: Unable to handle kernel data access on read at 0xc00000006be21300 Oops: Kernel access of bad area, sig: 11 [#1] MSR: 8000000000001003 <SF,ME,RI,LE> CR: 88222248 XER: 00000005 CFAR: c00000000003ffc4 DAR: c00000006be21300 DSISR: 40000000 IRQMASK: 0 NIP [c000000000029e40] arch_irq_work_raise+0x10/0x70 LR [c00000000003ffc8] machine_check_queue_event+0xa8/0x150 Call Trace: [c0000000179d3c70] [c00000000003ff64] machine_check_queue_event+0x44/0x150 [c0000000179d3d30] [c0000000000084e0] machine_check_early_common+0x1f0/0x2c0 The crash occurs because arch_irq_work_raise() calls preempt_disable() from machine check exception (MCE) handlers running in real mode. In this context, accessing the preempt_count can fault, leading to the panic. The preempt_disable()/preempt_enable() pair in arch_irq_work_raise() was originally added by commit 0fe1ac48bef0 ("powerpc/perf_event: Fix oops due to perf_event_do_pending call") to avoid races while raising irq work from exception context. Later, commit 471ba0e686cb ("irq_work: Do not raise an IPI when queueing work on the local CPU") added preemption protection in irq_work_queue() path, while commit 20b876918c06 ("irq_work: Use per cpu atomics instead of regular atomics") added equivalent protection in irq_work_queue_on() before reaching arch_irq_work_raise(): irq_work_queue() / irq_work_queue_on() -> preempt_disable() -> __irq_work_queue_local() -> irq_work_raise() -> arch_irq_work_raise() As a result, callers other than mce_irq_work_raise() already execute with preemption disabled, making the additional preempt_disable()/preempt_enable() pair in arch_irq_work_raise() redundant. The arch_irq_work_raise() function executes in NMI context when called from MCE handler. Hence we will not be preempted or scheduled out since we are in NMI context with MSR[EE]=0. Therefore, it is safe to remove the preempt_disable()/preempt_enable() calls from here. Remove it to avoid accessing preempt_count from real mode context. [Maddy: Fixed the commit title]
INFO
Published Date :
July 24, 2026, 4:16 p.m.
Last Modified :
July 24, 2026, 4:16 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Affected Products
The following products are affected by CVE-2026-64214
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
Solution
- Remove preempt_disable() and preempt_enable() calls.
- Update the Linux kernel to a patched version.
- Apply the fix for powerpc/time.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-64214.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-64214 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-64214
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-64214 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-64214 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jul. 24, 2026
Action Type Old Value New Value Added Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': 'cc15ff3275694fedc33cd3d53212a43eec7aa0bc', 'lessThan': '51860e423592893cd7bfa7287d99a3aff4dc3a9d', 'versionType': 'git'}, {'status': 'affected', 'version': 'cc15ff3275694fedc33cd3d53212a43eec7aa0bc', 'lessThan': 'a09d07ac45e283c9861a9ceea06f56d0ba851d22', 'versionType': 'git'}, {'status': 'affected', 'version': 'cc15ff3275694fedc33cd3d53212a43eec7aa0bc', 'lessThan': '72d8d1c36452a4d3ee134b1da48de7518c1329f9', 'versionType': 'git'}, {'status': 'affected', 'version': 'cc15ff3275694fedc33cd3d53212a43eec7aa0bc', 'lessThan': '6dcd072a5ae3aed336e4a67a7d4cc5205b240065', 'versionType': 'git'}, {'status': 'affected', 'version': 'cc15ff3275694fedc33cd3d53212a43eec7aa0bc', 'lessThan': '8079acc5ee5235a627e4586d4f42082a9000ea64', 'versionType': 'git'}, {'status': 'affected', 'version': 'cc15ff3275694fedc33cd3d53212a43eec7aa0bc', 'lessThan': '31467b23823ffec1f6fff407f8e3ca9af8b7491a', 'versionType': 'git'}], 'programFiles': ['arch/powerpc/kernel/time.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '5.18'}, {'status': 'unaffected', 'version': '0', 'lessThan': '5.18', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '6.1.175', 'versionType': 'semver', 'lessThanOrEqual': '6.1.*'}, {'status': 'unaffected', 'version': '6.6.142', 'versionType': 'semver', 'lessThanOrEqual': '6.6.*'}, {'status': 'unaffected', 'version': '6.12.92', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.34', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.0.11', 'versionType': 'semver', 'lessThanOrEqual': '7.0.*'}, {'status': 'unaffected', 'version': '7.1', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['arch/powerpc/kernel/time.c'], 'defaultStatus': 'affected'}] Added Description In the Linux kernel, the following vulnerability has been resolved: powerpc/time: Remove redundant preempt_disable|enable() calls from arch_irq_work_raise() A kernel panic is observed when handling machine check exceptions from real mode. BUG: Unable to handle kernel data access on read at 0xc00000006be21300 Oops: Kernel access of bad area, sig: 11 [#1] MSR: 8000000000001003 <SF,ME,RI,LE> CR: 88222248 XER: 00000005 CFAR: c00000000003ffc4 DAR: c00000006be21300 DSISR: 40000000 IRQMASK: 0 NIP [c000000000029e40] arch_irq_work_raise+0x10/0x70 LR [c00000000003ffc8] machine_check_queue_event+0xa8/0x150 Call Trace: [c0000000179d3c70] [c00000000003ff64] machine_check_queue_event+0x44/0x150 [c0000000179d3d30] [c0000000000084e0] machine_check_early_common+0x1f0/0x2c0 The crash occurs because arch_irq_work_raise() calls preempt_disable() from machine check exception (MCE) handlers running in real mode. In this context, accessing the preempt_count can fault, leading to the panic. The preempt_disable()/preempt_enable() pair in arch_irq_work_raise() was originally added by commit 0fe1ac48bef0 ("powerpc/perf_event: Fix oops due to perf_event_do_pending call") to avoid races while raising irq work from exception context. Later, commit 471ba0e686cb ("irq_work: Do not raise an IPI when queueing work on the local CPU") added preemption protection in irq_work_queue() path, while commit 20b876918c06 ("irq_work: Use per cpu atomics instead of regular atomics") added equivalent protection in irq_work_queue_on() before reaching arch_irq_work_raise(): irq_work_queue() / irq_work_queue_on() -> preempt_disable() -> __irq_work_queue_local() -> irq_work_raise() -> arch_irq_work_raise() As a result, callers other than mce_irq_work_raise() already execute with preemption disabled, making the additional preempt_disable()/preempt_enable() pair in arch_irq_work_raise() redundant. The arch_irq_work_raise() function executes in NMI context when called from MCE handler. Hence we will not be preempted or scheduled out since we are in NMI context with MSR[EE]=0. Therefore, it is safe to remove the preempt_disable()/preempt_enable() calls from here. Remove it to avoid accessing preempt_count from real mode context. [Maddy: Fixed the commit title] Added Reference https://git.kernel.org/stable/c/31467b23823ffec1f6fff407f8e3ca9af8b7491a Added Reference https://git.kernel.org/stable/c/51860e423592893cd7bfa7287d99a3aff4dc3a9d Added Reference https://git.kernel.org/stable/c/6dcd072a5ae3aed336e4a67a7d4cc5205b240065 Added Reference https://git.kernel.org/stable/c/72d8d1c36452a4d3ee134b1da48de7518c1329f9 Added Reference https://git.kernel.org/stable/c/8079acc5ee5235a627e4586d4f42082a9000ea64 Added Reference https://git.kernel.org/stable/c/a09d07ac45e283c9861a9ceea06f56d0ba851d22