CVE-2026-23042 in Linux
Summary
by MITRE • 02/04/2026
In the Linux kernel, the following vulnerability has been resolved:
idpf: fix aux device unplugging when rdma is not supported by vport
If vport flags do not contain VIRTCHNL2_VPORT_ENABLE_RDMA, driver does not allocate vdev_info for this vport. This leads to kernel NULL pointer dereference in idpf_idc_vport_dev_down(), which references vdev_info for every vport regardless.
Check, if vdev_info was ever allocated before unplugging aux device.
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Analysis
by VulDB Data Team • 04/30/2026
This vulnerability exists within the Linux kernel's implementation of the Intel Data Plane Framework driver specifically affecting the idpf module. The issue manifests when handling auxiliary device unplugging operations in environments where RDMA support is not enabled for certain virtual ports. The root cause stems from improper memory management and conditional logic within the driver's device lifecycle handling. When a virtual port lacks the VIRTCHNL2_VPORT_ENABLE_RDMA flag, the driver intentionally avoids allocating vdev_info structure for that port, creating a scenario where subsequent operations attempt to reference uninitialized or freed memory structures.
The technical flaw occurs in the idpf_idc_vport_dev_down() function which processes device down operations regardless of whether vdev_info was allocated for each virtual port. This function performs a null pointer dereference when attempting to access vdev_info members without proper validation of the allocation status. The vulnerability represents a classic null pointer dereference issue that can lead to kernel oops, system crashes, and potential denial of service conditions. This type of vulnerability is categorized under CWE-476 as Null Pointer Dereference, which is a common class of memory safety issues in kernel space programming.
The operational impact of this vulnerability is significant as it can cause system instability and complete kernel crashes when auxiliary devices are unplugged from virtual ports that do not support RDMA functionality. Attackers could potentially exploit this condition to cause system denial of service by repeatedly triggering device unplugging operations on affected virtual ports. The vulnerability affects systems using Intel Data Plane Framework implementations where virtual ports may be configured without RDMA support, particularly in virtualized environments with network virtualization capabilities. The issue demonstrates a fundamental flaw in resource management where the driver fails to maintain consistency between device state and allocated resources.
Mitigation strategies should focus on implementing proper null pointer checks before accessing vdev_info structures in the device down operation path. The fix requires adding conditional validation to ensure vdev_info was allocated before attempting to reference it during device unplugging operations. System administrators should ensure all kernel updates are applied promptly to address this vulnerability. Additionally, monitoring for kernel oops messages and system crashes related to the idpf driver should be implemented. The vulnerability highlights the importance of proper resource lifecycle management in kernel drivers and adherence to security best practices as outlined in the ATT&CK framework for kernel-level threats, specifically targeting privilege escalation and system stability compromise techniques. Organizations should also consider implementing automated patch management processes to ensure timely deployment of kernel security updates and maintain system integrity against such memory safety vulnerabilities.