CVE-2026-23022 Overview
A memory leak vulnerability has been identified in the Linux kernel's Intel Data Plane Function (idpf) network driver. The issue occurs in the idpf_vc_core_deinit() function, which fails to properly free the hw->lan_regs memory allocation during driver deinitialization. This vulnerability was discovered through kmemleak reports during reset operations, revealing unreferenced objects that accumulate over time.
Critical Impact
Memory resources are not properly released during idpf driver deinitialization, potentially leading to system memory exhaustion over time, particularly on systems that frequently reset network interfaces or experience driver reloads.
Affected Products
- Linux kernel with idpf (Intel Data Plane Function) driver module
- Systems utilizing Intel network hardware supported by the idpf driver
- Linux kernel versions prior to the security patch
Discovery Timeline
- 2026-01-31 - CVE CVE-2026-23022 published to NVD
- 2026-02-03 - Last updated in NVD database
Technical Details for CVE-2026-23022
Vulnerability Analysis
The vulnerability exists in the idpf network driver's core deinitialization routine. When the driver initializes via idpf_vc_core_init(), memory is allocated for hw->lan_regs using __kmalloc_noprof(). However, when the driver deinitializes through idpf_vc_core_deinit(), this allocated memory is not freed, resulting in a memory leak.
The kmemleak tool detected this issue during reset operations, capturing unreferenced memory objects of 96 bytes each. The backtrace shows the allocation originating from idpf_vc_core_init() during workqueue processing (process_one_work) in kernel worker threads.
Root Cause
The root cause is a missing kfree() or equivalent deallocation call for the hw->lan_regs pointer in the idpf_vc_core_deinit() function. During driver initialization, memory is allocated for LAN registers mapping, but the corresponding cleanup path neglects to release this memory when the driver is deinitialized or during reset sequences.
This is a classic resource leak pattern where allocation and deallocation paths are asymmetric. Each time the driver goes through a reset cycle or is reinitialized, an additional 96-byte memory block becomes orphaned and unreclaimable.
Attack Vector
While this vulnerability is classified with an unknown attack vector, the practical impact is through local system resource exhaustion:
The memory leak is triggered during normal driver operations, particularly during:
- Network interface resets
- Driver module unload/reload cycles
- System suspend/resume operations that reinitialize network hardware
- Hot-plug events for supported network devices
Over extended periods or with frequent reset operations, the accumulated leaked memory can degrade system performance and potentially lead to denial of service conditions due to memory exhaustion.
Detection Methods for CVE-2026-23022
Indicators of Compromise
- Gradual increase in kernel memory usage without corresponding process allocation
- kmemleak reports showing unreferenced objects from idpf_vc_core_init() backtrace
- System logs indicating memory pressure on systems with Intel idpf-supported network hardware
- Unexplained memory exhaustion on servers with frequent network interface resets
Detection Strategies
- Enable and monitor kmemleak on systems running the idpf driver for unreferenced object reports
- Implement memory usage trending and alerting for kernel slab allocations
- Monitor /proc/meminfo for unexpected increases in unreclaimable slab memory
- Use slabtop or similar tools to track kmalloc cache growth patterns
Monitoring Recommendations
- Configure automated kmemleak scans on systems with idpf network devices
- Set up alerts for abnormal kernel memory growth patterns
- Monitor system stability during and after network interface reset operations
- Track driver module load/unload events correlated with memory consumption
How to Mitigate CVE-2026-23022
Immediate Actions Required
- Apply the kernel patch that adds proper memory deallocation in idpf_vc_core_deinit()
- Reduce the frequency of network interface resets where possible
- Monitor affected systems for memory exhaustion symptoms
- Plan kernel updates to include the fix during next maintenance window
Patch Information
The fix has been committed to the stable Linux kernel tree. The patch ensures that hw->lan_regs is properly freed during driver deinitialization. The relevant commits can be found at:
System administrators should update to a kernel version containing these commits or apply the patches to their existing kernel builds.
Workarounds
- Minimize network interface reset operations on affected systems until patched
- Implement periodic system reboots as a temporary measure to reclaim leaked memory
- Consider disabling the idpf driver if alternative network drivers are available for your hardware
- Monitor memory consumption and schedule proactive reboots before exhaustion occurs
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
