CVE-2022-50465 in Linux
Summary
by MITRE • 10/01/2025
In the Linux kernel, the following vulnerability has been resolved:
ext4: fix leaking uninitialized memory in fast-commit journal
When space at the end of fast-commit journal blocks is unused, make sure to zero it out so that uninitialized memory is not leaked to disk.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 01/17/2026
The vulnerability CVE-2022-50465 addresses a critical memory handling flaw within the ext4 filesystem implementation of the Linux kernel. This issue specifically affects the fast-commit journal mechanism, which is designed to optimize filesystem operations by reducing the overhead associated with traditional journaling approaches. The vulnerability arises from improper memory initialization practices during the fast-commit journal processing, creating potential security implications through information disclosure mechanisms.
The technical flaw occurs when the ext4 filesystem allocates space at the end of fast-commit journal blocks that remains unused. Rather than properly zeroing out this uninitialized memory region, the kernel leaves residual data from previous operations intact within these blocks. This uninitialized memory can contain sensitive information such as cryptographic keys, passwords, or other system data that was previously stored in the memory locations. When these journal blocks are written to disk, the leftover data becomes permanently persisted and accessible to unauthorized parties, creating a significant information disclosure vulnerability.
From an operational impact perspective, this vulnerability represents a serious security concern that can affect systems running Linux kernels with ext4 filesystems and fast-commit enabled. The leak of uninitialized memory can expose sensitive data that was previously processed by the kernel, potentially compromising system security. This vulnerability is particularly concerning in environments where multiple applications or users share the same filesystem, as information from one process could inadvertently leak to another through the journaling mechanism. The issue affects systems where fast-commit functionality is actively used, which is common in modern Linux distributions for improved performance.
The vulnerability aligns with CWE-1306, which addresses improper initialization of memory, and can be categorized under ATT&CK technique T1552.001 for unsecured credentials and T1552.004 for unsecured data storage. These classifications reflect the information disclosure nature of the vulnerability and its potential to expose sensitive data through improper memory handling practices. The flaw demonstrates a classic case of information leakage through uninitialized memory access, where the kernel fails to properly sanitize memory regions before persisting them to storage.
Mitigation strategies for CVE-2022-50465 primarily involve applying the relevant kernel security patches that address the uninitialized memory handling in the ext4 fast-commit journal implementation. System administrators should prioritize updating their Linux kernels to versions that include the fix, particularly those that have incorporated the specific memory sanitization changes for fast-commit journal blocks. Organizations should also conduct thorough security assessments to identify systems running affected kernel versions and ensure proper patch management procedures are in place. Additionally, monitoring for potential information leakage incidents and implementing proper memory sanitization practices in custom filesystem implementations can help prevent similar vulnerabilities from occurring in other components of the system.