CVE-2026-64073irq_work: Fix use-after-free in irq_work_single() on PREEMPT_RT
- 7.8HighCVSS base score
- 0.13%Exploitation in 30 daysEPSS · top 97% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
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.
Timeline
ID reserved
By Linux
Published
- 3 months later
· 3 months later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| LinuxCNA (assigner) | 3.1 | High7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
| NVDNVD · Modified | 3.1 | High7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 0.13% · top 97% of all CVEs (12 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.8.
Affected products
- affected 810979682ccc98dbd83f341c18a2e556c30a7164 – < 2dc79362302922cb18f35e262712b5e58de65442
- affected 810979682ccc98dbd83f341c18a2e556c30a7164 – < eef4f71b46a9929ac33e968538c9dd5d96a02460
- affected 810979682ccc98dbd83f341c18a2e556c30a7164 – < 684a78183c54c23e70d1cba320f7fc184604210b
- affected 810979682ccc98dbd83f341c18a2e556c30a7164 – < 18c0456ea2615b1a743a6db739c74411c3b42bc6
- affected 810979682ccc98dbd83f341c18a2e556c30a7164 – < 81b582784518196eff1050212a046bc29d3a05dd
- affected 810979682ccc98dbd83f341c18a2e556c30a7164 – < 91840be8f710370607f949a627e070896faeddb8
- affected 5.16
- unaffected < 5.16
- unaffected 6.1.175 – ≤ 6.1.*
- unaffected 6.6.142 – ≤ 6.6.*
- unaffected 6.12.92 – ≤ 6.12.*
- unaffected 6.18.34 – ≤ 6.18.*
- unaffected 7.0.11 – ≤ 7.0.*
- unaffected 7.1 – ≤ *
References
References6
- https://git.kernel.org/stable/c/2dc79362302922cb18f35e262712b5e58de65442 (opens in a new tab)
- https://git.kernel.org/stable/c/eef4f71b46a9929ac33e968538c9dd5d96a02460 (opens in a new tab)
- https://git.kernel.org/stable/c/684a78183c54c23e70d1cba320f7fc184604210b (opens in a new tab)
- https://git.kernel.org/stable/c/18c0456ea2615b1a743a6db739c74411c3b42bc6 (opens in a new tab)
- https://git.kernel.org/stable/c/81b582784518196eff1050212a046bc29d3a05dd (opens in a new tab)
- https://git.kernel.org/stable/c/91840be8f710370607f949a627e070896faeddb8 (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-45646 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-64073)Record last updated .