CVE-2023-53285 in Linux
Summary
by MITRE • 09/16/2025
In the Linux kernel, the following vulnerability has been resolved:
ext4: add bounds checking in get_max_inline_xattr_value_size()
Normally the extended attributes in the inode body would have been checked when the inode is first opened, but if someone is writing to the block device while the file system is mounted, it's possible for the inode table to get corrupted. Add bounds checking to avoid reading beyond the end of allocated memory if this happens.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 01/11/2026
The vulnerability identified as CVE-2023-53285 resides within the ext4 file system implementation of the Linux kernel, specifically in the function get_max_inline_xattr_value_size(). This flaw represents a classic buffer overflow condition that could potentially lead to system instability or security compromise. The vulnerability manifests when extended attributes are stored directly within the inode structure, a feature designed to optimize performance by reducing disk I/O operations for small metadata values. The core issue arises from inadequate bounds checking during the processing of inline extended attributes, creating a scenario where memory access violations could occur under specific corruption conditions.
The technical flaw stems from the absence of proper validation when processing extended attribute values that are stored within the inode structure itself. When an inode is first opened, normal validation procedures should ensure that extended attribute data remains within allocated memory boundaries. However, the vulnerability becomes exploitable when concurrent write operations to the block device occur while the file system remains mounted. This race condition scenario can lead to inode table corruption where the metadata structure becomes inconsistent with the actual data layout. The lack of bounds checking in get_max_inline_xattr_value_size() means that when the system attempts to read extended attribute values from corrupted inodes, it may access memory locations beyond the allocated buffer space, potentially causing kernel memory corruption or information disclosure.
The operational impact of this vulnerability extends beyond simple system instability to potentially enable more sophisticated attack vectors. While the immediate consequence involves kernel memory corruption that could lead to system crashes or denial of service conditions, the underlying memory access violation creates opportunities for information leakage or privilege escalation. Attackers who can induce the specific race condition scenario or manipulate file system corruption conditions may exploit this vulnerability to gain unauthorized access to kernel memory contents or potentially execute arbitrary code with kernel privileges. The vulnerability aligns with CWE-129 Input Validation and CWE-787 Out-of-bounds Write categories, representing a critical weakness in the kernel's memory management and validation mechanisms. From an attack perspective, this vulnerability could be leveraged as part of broader exploitation chains, particularly in environments where persistent file system corruption or concurrent access patterns are possible.
Mitigation strategies for CVE-2023-53285 focus on both immediate patch implementation and operational hardening measures. The primary solution involves applying the kernel patch that introduces proper bounds checking within the get_max_inline_xattr_value_size() function, ensuring that all extended attribute operations validate memory boundaries before access. System administrators should prioritize updating to kernel versions containing the fix, as this vulnerability represents a critical security risk that could be exploited in targeted attacks. Operational mitigations include implementing proper file system monitoring to detect unusual write patterns that might lead to corruption conditions, establishing robust backup and recovery procedures, and ensuring that file system operations are properly synchronized to prevent concurrent access conflicts. The vulnerability demonstrates the importance of defensive programming practices in kernel space, where every memory access must be validated against allocated boundaries to prevent exploitation opportunities that could compromise entire system integrity. Organizations should also consider implementing intrusion detection systems that monitor for unusual file system behavior patterns that might indicate exploitation attempts or environmental conditions conducive to this vulnerability.