CVE-2025-38167 in Linux
Summary
by MITRE • 07/03/2025
In the Linux kernel, the following vulnerability has been resolved:
fs/ntfs3: handle hdr_first_de() return value
The hdr_first_de() function returns a pointer to a struct NTFS_DE. This pointer may be NULL. To handle the NULL error effectively, it is important to implement an error handler. This will help manage potential errors consistently.
Additionally, error handling for the return value already exists at other points where this function is called.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
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Analysis
by VulDB Data Team • 04/18/2026
The vulnerability identified as CVE-2025-38167 resides within the Linux kernel's ntfs3 filesystem driver, specifically concerning the improper handling of the hdr_first_de() function return value. This function is designed to return a pointer to a struct NTFS_DE structure that contains directory entry information for ntfs3 filesystems. The core issue emerges from the fact that this function can legitimately return a NULL pointer under certain error conditions, yet the existing code implementation fails to adequately check for this NULL return value before proceeding with operations that assume a valid pointer exists. The vulnerability represents a classic null pointer dereference scenario that could potentially lead to system instability or denial of service conditions.
The technical flaw manifests in the ntfs3 filesystem driver's failure to implement proper error handling for the hdr_first_de() function call, creating a potential execution path where a NULL pointer is dereferenced. According to CWE-476, this vulnerability falls under the category of NULL Pointer Dereference, where a pointer that is expected to point to a valid memory location instead contains NULL, leading to a crash or unexpected behavior. The Linux Verification Center's SVACE tool identified this weakness through systematic code analysis, highlighting the importance of proper error handling in kernel space operations. The vulnerability's impact is particularly concerning because it exists within the filesystem layer where the kernel handles critical data access operations, potentially affecting system stability when processing ntfs3 filesystem structures.
The operational impact of CVE-2025-38167 extends beyond simple system crashes, as it represents a potential attack vector that could be exploited to cause denial of service conditions or system instability. When the ntfs3 filesystem driver encounters malformed or corrupted ntfs3 filesystem structures, the failure to properly handle the NULL return value from hdr_first_de() could result in kernel panics or forced system reboots. This vulnerability directly aligns with ATT&CK technique T1499.001 for Network Denial of Service, as it could potentially be leveraged to disrupt filesystem operations and system availability. The presence of existing error handling patterns elsewhere in the same codebase suggests that the developers were aware of proper error handling procedures, making this particular oversight more significant from a security perspective.
Mitigation strategies for CVE-2025-38167 should focus on implementing comprehensive error checking around the hdr_first_de() function calls within the ntfs3 filesystem driver. The fix requires adding proper NULL pointer validation before any operations are performed on the returned pointer, ensuring that the code gracefully handles error conditions rather than attempting to dereference potentially invalid memory locations. Security practitioners should prioritize applying kernel updates that contain the patched ntfs3 driver implementation, as this vulnerability affects the core filesystem functionality that multiple system components depend upon. Additionally, system administrators should monitor for any signs of filesystem corruption or unusual system behavior that might indicate exploitation attempts, particularly when dealing with ntfs3 mounted filesystems. The fix should also include enhanced logging capabilities to help identify when error conditions occur in the ntfs3 driver, providing better visibility into potential exploitation attempts or system issues related to ntfs3 filesystem operations.