CVE-2025-68728

Vulnerability

CVE-2025-68728 is a bug in the Linux kernel's ntfs3 file system driver. When mi_format_new calls ntfs_get_bh() after a failing mi_read, the buffer obtained via sb_getblk() may not be brought up-to-date. The driver sets the buffer as up-to-date without ensuring its contents are initialized, potentially leaving uninitialized (uninit) memory in the MFT record [1] [2].

Exploitation

The vulnerability is triggered through crafted NTFS filesystem operations that cause the mi_read call to fail. An attacker would need the ability to mount a maliciously crafted NTFS volume — typically requiring local access or a user-space utility that mounts a filesystem. No special privileges beyond the ability to trigger the erroneous code path are required; the bug manifests during normal metadata structure formatting [3].

Impact

The primary impact is information disclosure: KMSAN (Kernel Memory Sanitizer) detects the uninit memory and warns of potential exposure of kernel heap data to user-space or to other parts of the kernel. An attacker may be able to leverage the uninitialized data to leak sensitive information, though the official description does not assert arbitrary code execution [1] [2].

Mitigation

Patches have been submitted to the Linux kernel stable tree and are available through the referenced commits [1][2][3]. Users should update their kernel to a version containing the fix. No workaround is provided, but the bug is only reachable when mounting a malicious NTFS filesystem, so limiting access to mount operations reduces risk.