CVE-2026-64073
irq_work: Fix use-after-free in irq_work_single() on PREEMPT_RT
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.
INFO
Published Date :
July 19, 2026, 4:17 p.m.
Last Modified :
July 19, 2026, 4:17 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Affected Products
The following products are affected by CVE-2026-64073
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
Solution
- Update the Linux kernel.
- Ensure RCU read-side critical sections are used.
- Add synchronize_rcu() in irq_work_sync().
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-64073.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-64073 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-64073
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-64073 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-64073 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jul. 19, 2026
Action Type Old Value New Value Added Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '810979682ccc98dbd83f341c18a2e556c30a7164', 'lessThan': '2dc79362302922cb18f35e262712b5e58de65442', 'versionType': 'git'}, {'status': 'affected', 'version': '810979682ccc98dbd83f341c18a2e556c30a7164', 'lessThan': 'eef4f71b46a9929ac33e968538c9dd5d96a02460', 'versionType': 'git'}, {'status': 'affected', 'version': '810979682ccc98dbd83f341c18a2e556c30a7164', 'lessThan': '684a78183c54c23e70d1cba320f7fc184604210b', 'versionType': 'git'}, {'status': 'affected', 'version': '810979682ccc98dbd83f341c18a2e556c30a7164', 'lessThan': '18c0456ea2615b1a743a6db739c74411c3b42bc6', 'versionType': 'git'}, {'status': 'affected', 'version': '810979682ccc98dbd83f341c18a2e556c30a7164', 'lessThan': '81b582784518196eff1050212a046bc29d3a05dd', 'versionType': 'git'}, {'status': 'affected', 'version': '810979682ccc98dbd83f341c18a2e556c30a7164', 'lessThan': '91840be8f710370607f949a627e070896faeddb8', 'versionType': 'git'}], 'programFiles': ['kernel/irq_work.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '5.16'}, {'status': 'unaffected', 'version': '0', 'lessThan': '5.16', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '6.1.175', 'versionType': 'semver', 'lessThanOrEqual': '6.1.*'}, {'status': 'unaffected', 'version': '6.6.142', 'versionType': 'semver', 'lessThanOrEqual': '6.6.*'}, {'status': 'unaffected', 'version': '6.12.92', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.34', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.0.11', 'versionType': 'semver', 'lessThanOrEqual': '7.0.*'}, {'status': 'unaffected', 'version': '7.1', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['kernel/irq_work.c'], 'defaultStatus': 'affected'}] Added 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. Added Reference https://git.kernel.org/stable/c/18c0456ea2615b1a743a6db739c74411c3b42bc6 Added Reference https://git.kernel.org/stable/c/2dc79362302922cb18f35e262712b5e58de65442 Added Reference https://git.kernel.org/stable/c/684a78183c54c23e70d1cba320f7fc184604210b Added Reference https://git.kernel.org/stable/c/81b582784518196eff1050212a046bc29d3a05dd Added Reference https://git.kernel.org/stable/c/91840be8f710370607f949a627e070896faeddb8 Added Reference https://git.kernel.org/stable/c/eef4f71b46a9929ac33e968538c9dd5d96a02460