Overview
CVE-2025-40232 describes a type confusion vulnerability in the Linux kernel, specifically affecting the implementation of RV (Runtime Verification) monitors. This issue arises from inconsistencies in how the `enabled_monitors_seq_ops` callbacks handle iterators. Some callbacks incorrectly treated the iterator as `struct rv_monitor *` while others treated it as `struct list_head *`, leading to potential crashes due to incorrect type casting.
Technical Details
The vulnerability lies within the code responsible for managing enabled RV monitors in the Linux kernel. The `enabled_monitors_seq_ops` structure defines a set of sequence operations used for iterating through the list of enabled monitors. Due to inconsistencies in the implementation of these operations, the iterator type was misinterpreted. This mismatch could lead to a wrong type cast, ultimately resulting in a system crash as reported by Nathan.
The fix involves standardizing the iterator type used by all callbacks in `enabled_monitors_seq_ops` to `struct list_head *`. This ensures consistency and eliminates the possibility of type confusion. The patch also aligns the implementation with the `available_monitors` list, which already uses `struct list_head *` as its iterator.
CVSS Analysis
Currently, a CVSS score is not available (N/A) for CVE-2025-40232. While the vulnerability can lead to a system crash, which is a denial-of-service, the exploitability and scope of the vulnerability require further analysis. The lack of a CVSS score suggests that either the vulnerability is difficult to exploit or more information is needed to accurately assess its severity.
Possible Impact
The primary impact of CVE-2025-40232 is a denial-of-service (DoS) condition. A successful exploitation of this vulnerability can lead to a system crash. The consequences of a system crash can include data loss, system downtime, and potential service interruptions. The severity of the impact will depend on the criticality of the affected system.
Mitigation or Patch Steps
The recommended mitigation for CVE-2025-40232 is to apply the patch provided by the Linux kernel developers. The fix has been incorporated into stable kernel releases. To mitigate this vulnerability, you should:
- Update your kernel: Upgrade your Linux kernel to a version containing the fix for CVE-2025-40232. Consult your distribution’s security advisories for specific instructions on how to update your kernel.
- Monitor for updates: Regularly monitor security advisories from your Linux distribution and the kernel community for any new information or updated patches related to this vulnerability.
References
Kernel Commit 1: Fix for CVE-2025-40232
Kernel Commit 2: Fix for CVE-2025-40232
