SB20260720165 - Use-after-free in Linux kernel irq_work_single()
Published: July 20, 2026
Security Bulletin ID
SB20260720165
CSH Severity
Low
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Local access
Highest impact
Denial of service
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 vulnerability.
1) Use-after-free (CVE-ID: CVE-2026-64073)
CWE-ID: CWE-416 - Use After Free
CVSSv4: 5.7 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to a use-after-free in irq_work_single() when synchronizing irq_work on PREEMPT_RT systems. A local user can trigger concurrent irq_work activity and free the work structure after BUSY is cleared to cause a denial of service.
The issue affects non-HARD irq_work processed by per-CPU kthreads on PREEMPT_RT.
Remediation
Install update from vendor's website.
References
- 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