CVE-2026-64073

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 v3 7.8 HIGH

7.8^/10

CVSS v3 : HIGH

Vector :

Exploitability : 1.8 / Impact : 5.9

Attack Vector LOCAL

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://git.kernel.org/stable/c/18c0456ea2615b1a743a6db739c74411c3b42bc6
https://git.kernel.org/stable/c/2dc79362302922cb18f35e262712b5e58de65442
https://git.kernel.org/stable/c/684a78183c54c23e70d1cba320f7fc184604210b
https://git.kernel.org/stable/c/81b582784518196eff1050212a046bc29d3a05dd
https://git.kernel.org/stable/c/91840be8f710370607f949a627e070896faeddb8
https://git.kernel.org/stable/c/eef4f71b46a9929ac33e968538c9dd5d96a02460

Configurations

No configuration.

History

20 Jul 2026, 15:17

Type	Values Removed	Values Added
CVSS	v2 : ~~unknown~~ v3 : ~~unknown~~	v2 : unknown v3 : 7.8

19 Jul 2026, 16:17

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-07-19 16:17

Updated : 2026-07-20 15:17

NVD link : CVE-2026-64073

Mitre link : CVE-2026-64073

CVE.ORG link : CVE-2026-64073

JSON object : View

Products Affected

No product.

CWE

No CWE.

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