CVE-2026-64073 (GCVE-0-2026-64073)
Vulnerability from cvelistv5 – Published: 2026-07-19 15:39 – Updated: 2026-08-05 12:38
VLAI
EPSS
VEX
Title
irq_work: Fix use-after-free in irq_work_single() on PREEMPT_RT
Summary
In the Linux kernel, the following vulnerability has been resolved:
irq_work: Fix use-after-free in irq_work_single() on PREEMPT_RT
On PREEMPT_RT, non-HARD irq_work runs in per-CPU kthreads via
run_irq_workd(), so irq_work_sync() uses rcuwait() to wait for BUSY==0.
After irq_work_single() clears BUSY via atomic_cmpxchg(), it still
dereferences @work for irq_work_is_hard() and rcuwait_wake_up().
An irq_work_sync() caller on another CPU that enters after BUSY is cleared
can observe BUSY==0 immediately, return, and free the work before those
accesses complete — causing a use-after-free.
Fix this by wrapping run_irq_workd() in guard(rcu)() so that the entire
irq_work_single() execution is within an RCU read-side critical
section. Then add synchronize_rcu() in irq_work_sync() after
rcuwait_wait_event() to ensure the caller waits for the RCU grace period
before returning, preventing premature frees.
Severity
7.8 (High)
Assigner
References
6 references
Impacted products
2 products
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| Linux | Linux |
Affected:
810979682ccc98dbd83f341c18a2e556c30a7164 , < 2dc79362302922cb18f35e262712b5e58de65442
(git)
Affected: 810979682ccc98dbd83f341c18a2e556c30a7164 , < eef4f71b46a9929ac33e968538c9dd5d96a02460 (git) Affected: 810979682ccc98dbd83f341c18a2e556c30a7164 , < 684a78183c54c23e70d1cba320f7fc184604210b (git) Affected: 810979682ccc98dbd83f341c18a2e556c30a7164 , < 18c0456ea2615b1a743a6db739c74411c3b42bc6 (git) Affected: 810979682ccc98dbd83f341c18a2e556c30a7164 , < 81b582784518196eff1050212a046bc29d3a05dd (git) Affected: 810979682ccc98dbd83f341c18a2e556c30a7164 , < 91840be8f710370607f949a627e070896faeddb8 (git) |
guessed | |
| Linux | Linux |
Affected:
5.16
Unaffected: 0 , < 5.16 (semver) Unaffected: 6.1.175 , ≤ 6.1.* (semver) Unaffected: 6.6.142 , ≤ 6.6.* (semver) Unaffected: 6.12.92 , ≤ 6.12.* (semver) Unaffected: 6.18.34 , ≤ 6.18.* (semver) Unaffected: 7.0.11 , ≤ 7.0.* (semver) Unaffected: 7.1 , ≤ * (original_commit_for_fix) |
guessed |
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}
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"id": "CVE-2026-64073",
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"source": "Red Hat CSAF VEX",
"status": "final",
"title": "kernel: irq_work: Fix use-after-free in irq_work_single() on PREEMPT_RT",
"url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-64073.json",
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"source": "SUSE CSAF VEX",
"status": "interim",
"title": "SUSE CVE CVE-2026-64073",
"url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-64073.json",
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Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
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Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.
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