CVE-2026-64214: powerpc/time: Remove redundant preempt_disable|enable() calls from arch_irq_work_raise()
Noroxi assessment
Priority: Monitor (action score 22/100)
- The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
- Probability of exploitation in the next 30 days: 0.12% (FIRST EPSS).
- Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
- Fixed version: Linux Linux 31467b23823ffec1f6fff407f8e3ca9af8b7491a, 51860e423592893cd7bfa7287d99a3aff4dc3a9d, 6dcd072a5ae3aed336e4a67a7d4cc5205b240065.
- Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).
Low priority for now. Upgrade to Linux Linux 31467b23823ffec1f6fff407f8e3ca9af8b7491a, 51860e423592893cd7bfa7287d99a3aff4dc3a9d, 6dcd072a5ae3aed336e4a67a7d4cc5205b240065 or later.
Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it
Primary sources: NVD · CVE.org · FIRST EPSS
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]
- Published
- Jul 24, 2026
- Updated
- Aug 11, 2026
- EPSS
- 0.1% · 2th percentile
- CWE
- CWE-476
Report tools
Action score
22
Monitor
Low priority for now.
- CVSS
- 22 / 40 · 5.5 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.1%
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- No public exploit code on record
- A fix has been released
If any of these changes, we'll tell you in the daily email digest.
Running WordPress? Scan your site free with WP Lens
Noroxi analysis
What does it mean in your environment?
The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.
We use this product, ask for helpAffected systems
Is your version affected?
Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.
| Vendor | Product | CPE |
|---|---|---|
| linux | linux kernel | cpe:2.3:o:linux:linux_kernel |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- linux linux kernel5.18 and later · before 6.1.175
- linux linux kernel6.2 and later · before 6.6.142
- linux linux kernel6.7 and later · before 6.12.92
- linux linux kernel6.13 and later · before 6.18.34
- linux linux kernel6.19 and later · before 7.0.11
- linux linux kernel7.1
Versions reported by the vendor
Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.
Linux Linux
- 5.18affected
- cc15ff3275694fedc33cd3d53212a43eec7aa0bc and later · before 51860e423592893cd7bfa7287d99a3aff4dc3a9daffected · git
- cc15ff3275694fedc33cd3d53212a43eec7aa0bc and later · before a09d07ac45e283c9861a9ceea06f56d0ba851d22affected · git
- cc15ff3275694fedc33cd3d53212a43eec7aa0bc and later · before 72d8d1c36452a4d3ee134b1da48de7518c1329f9affected · git
- cc15ff3275694fedc33cd3d53212a43eec7aa0bc and later · before 6dcd072a5ae3aed336e4a67a7d4cc5205b240065affected · git
- cc15ff3275694fedc33cd3d53212a43eec7aa0bc and later · before 8079acc5ee5235a627e4586d4f42082a9000ea64affected · git
- cc15ff3275694fedc33cd3d53212a43eec7aa0bc and later · before 31467b23823ffec1f6fff407f8e3ca9af8b7491aaffected · git
- before 5.18not affected · semver
- 6.1.175 and later · up to and including 6.1.*not affected · semver
- 6.6.142 and later · up to and including 6.6.*not affected · semver
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:12 | linux | before 6.1.176-1 | 6.1.176-1 |
| Debian:13 | linux | before 6.12.94-1 | 6.12.94-1 |
| Debian:14 | linux | before 7.0.12-1 | 7.0.12-1 |
Same product
linux: all recordsOther highest-scoring records for the same primary product.
- CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV90Now
- CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe KEV89Now
- CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV85Now
Published before and after this one in the same product
- ← EarlierCVE-2026-64209Jul 24, 2026 · phy: qcom: qmp-usbc: Fix out-of-bounds array access in dp swing config28Monitor
- ← EarlierCVE-2026-64211Jul 24, 2026 · srcu: Don't queue workqueue handlers to never-online CPUs22Monitor
- Later →CVE-2026-64215Jul 24, 2026 · drm/msm/a6xx: Check kzalloc return in a8xx_hfi_send_perf_table22Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| Linux Linux | 31467b23823ffec1f6fff407f8e3ca9af8b7491a | Vendor (CNA) |
| Linux Linux | 51860e423592893cd7bfa7287d99a3aff4dc3a9d | Vendor (CNA) |
| Linux Linux | 6dcd072a5ae3aed336e4a67a7d4cc5205b240065 | Vendor (CNA) |
| Linux Linux | 72d8d1c36452a4d3ee134b1da48de7518c1329f9 | Vendor (CNA) |
| Linux Linux | 8079acc5ee5235a627e4586d4f42082a9000ea64 | Vendor (CNA) |
| Linux Linux | a09d07ac45e283c9861a9ceea06f56d0ba851d22 | Vendor (CNA) |
| debian:linux | 6.1.176-1 · Debian:12 | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
National notice (Türkiye Cybersecurity Directorate / USOM)
Official security notices citing this record; remediation advice is on the agency's page.
- TR-26-0636 · Jul 27, 2026(Linux Kernel Güvenlik Bildirimi)
Technical details
Attack conditions
- Someone with local access to the system can trigger it.
- A low-privileged account is enough.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- none
- Integrity
- none
- Availability
- high · the service can be disrupted
- Attack vector
- Local
- Attack complexity
- Low
- Privileges required
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- None
- Integrity impact
- None
- Availability impact
- High
Weakness class (CWE)
CWE-476 · NULL Pointer DereferenceCVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
nvd-primary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (5 more)Show less
- git.kernel.org/stable/c/51860e423592893cd7bfa7287d99a3aff4dc3a9d
- git.kernel.org/stable/c/6dcd072a5ae3aed336e4a67a7d4cc5205b240065
- git.kernel.org/stable/c/72d8d1c36452a4d3ee134b1da48de7518c1329f9
- git.kernel.org/stable/c/8079acc5ee5235a627e4586d4f42082a9000ea64
- git.kernel.org/stable/c/a09d07ac45e283c9861a9ceea06f56d0ba851d22
Vendor advisories and official records. Exploit/PoC links are deliberately left out.