CVE-2026-64073irq_work: Fix use-after-free in irq_work_single() on PREEMPT_RT
Updated under an hour ago ()
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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.
- CVSS
- 7.8 HIGH (v3.1, CNA)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Weakness (CWE)
- Not given
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- Linux
- NVD analysis
- Analyzed
- Record last updated
- Oct 16, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Linux Linux linux:linux (from the name) | 810979682ccc98dbd83f341c18a2e556c30a7164 builds before 2dc79362302922cb18f35e262712b5e58de65442; from 810979682ccc98dbd83f341c18a2e556c30a7164 before eef4f71b46a9929ac33e968538c9dd5d96a02460; 810979682ccc98dbd83f341c18a2e556c30a7164 builds before 684a78183c54c23e70d1cba320f7fc184604210b; 810979682ccc98dbd83f341c18a2e556c30a7164 builds before 18c0456ea2615b1a743a6db739c74411c3b42bc6; 810979682ccc98dbd83f341c18a2e556c30a7164 builds before 81b582784518196eff1050212a046bc29d3a05dd; 810979682ccc98dbd83f341c18a2e556c30a7164 builds before 91840be8f710370607f949a627e070896faeddb8 | CNA record |
linux linux_kernel linux:linux_kernel | from 5.16 before 6.1.175; from 6.2 before 6.6.142; from 6.7 before 6.12.92; from 6.13 before 6.18.34; from 6.19 before 7.0.11; 7.1; 7.1; 7.1 | NVD |
References
- https://git.kernel.org/stable/c/2dc79362302922cb18f35e262712b5e58de65442patch
- https://git.kernel.org/stable/c/eef4f71b46a9929ac33e968538c9dd5d96a02460patch
- https://git.kernel.org/stable/c/684a78183c54c23e70d1cba320f7fc184604210bpatch
- https://git.kernel.org/stable/c/18c0456ea2615b1a743a6db739c74411c3b42bc6patch
- https://git.kernel.org/stable/c/81b582784518196eff1050212a046bc29d3a05ddpatch
- https://git.kernel.org/stable/c/91840be8f710370607f949a627e070896faeddb8patch
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.