CVE-2025-38656 in Linux
Summary
by MITRE • 08/22/2025
In the Linux kernel, the following vulnerability has been resolved:
wifi: iwlwifi: Fix error code in iwl_op_mode_dvm_start()
Preserve the error code if iwl_setup_deferred_work() fails. The current code returns ERR_PTR(0) (which is NULL) on this path. I believe the missing error code potentially leads to a use after free involving debugfs.
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Analysis
by VulDB Data Team • 05/29/2026
The vulnerability identified as CVE-2025-38656 resides within the Linux kernel's wireless subsystem, specifically affecting the iwlwifi driver implementation used for Intel wireless network adapters. This flaw manifests in the iwl_op_mode_dvm_start() function where improper error handling creates a potential use-after-free condition that could be exploited to compromise system integrity. The issue stems from a fundamental coding error in how the driver manages error states during the initialization process of deferred work structures, creating a pathway for memory corruption vulnerabilities.
The technical flaw occurs when the iwl_setup_deferred_work() function fails during the wireless driver initialization sequence. Current implementation fails to properly propagate the error code returned by this function, instead returning ERR_PTR(0) which effectively translates to a NULL pointer value. This incorrect error handling creates a scenario where the driver continues execution as if initialization succeeded, while in reality critical data structures may not have been properly established. The CWE-252 weakness classification applies here as the code fails to check for error conditions, leading to an improper handling of exceptional situations. This error propagation failure directly impacts the driver's ability to maintain consistent state management throughout its operational lifecycle.
The operational impact of this vulnerability extends beyond simple functional failure to encompass potential security implications within the kernel's memory management subsystem. When the error code is not properly preserved, the debugfs interface associated with the wireless driver can be accessed with invalid memory pointers, creating opportunities for use-after-free conditions that adversaries could potentially exploit. The ATT&CK framework's T1068 technique for Exploitation for Privilege Escalation becomes relevant as this vulnerability could enable attackers to manipulate kernel memory structures through crafted wireless network operations. The memory corruption resulting from this flaw could allow for arbitrary code execution with kernel privileges, potentially leading to complete system compromise.
Mitigation strategies for CVE-2025-38656 should prioritize immediate patch application from trusted sources, as the vulnerability directly affects kernel stability and security. System administrators should ensure all wireless network adapters using the iwlwifi driver receive updated firmware and kernel modules. Additional protective measures include implementing kernel lockdown mechanisms and restricting debugfs access to privileged users only. The fix requires proper error code preservation in the iwl_op_mode_dvm_start() function to ensure that any failure in iwl_setup_deferred_work() properly propagates back to the calling function, preventing execution paths that could lead to memory corruption. Monitoring for anomalous wireless driver behavior and implementing proper kernel memory validation checks can help detect exploitation attempts. Organizations should also consider network segmentation strategies to limit potential attack surface exposure while patches are deployed, as the vulnerability affects core kernel functionality essential for wireless communications.