CVE-2023-52602 in Linux
Summary
by MITRE • 03/06/2024
In the Linux kernel, the following vulnerability has been resolved:
jfs: fix slab-out-of-bounds Read in dtSearch
Currently while searching for current page in the sorted entry table of the page there is a out of bound access. Added a bound check to fix the error.
Dave: Set return code to -EIO
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Analysis
by VulDB Data Team • 06/19/2025
The vulnerability identified as CVE-2023-52602 affects the Linux kernel's JFS (Journaled File System) implementation, specifically within the dtSearch function responsible for searching within sorted entry tables of pages. This represents a critical out-of-bounds read condition that could potentially lead to system instability or information disclosure. The flaw occurs during the page search operation within the JFS subsystem where the kernel attempts to access memory locations beyond the allocated bounds of the entry table structure. Such memory access violations typically arise from insufficient boundary validation during array or buffer operations, creating opportunities for attackers to exploit the system through carefully crafted inputs that trigger the vulnerable code path.
The technical implementation of this vulnerability stems from inadequate bounds checking within the dtSearch function of the JFS module. When processing sorted entry tables during page searches, the kernel fails to validate that array indices remain within legitimate bounds before accessing memory locations. This particular flaw manifests as a slab-out-of-bounds read, indicating that the memory access occurs within kernel memory slabs that are managed by the kernel's memory allocator. The vulnerability is classified under CWE-129 as an Improper Validation of Array Index, which directly relates to the lack of proper boundary checks in array access operations. The fix implemented by Dave involves adding explicit bounds validation to prevent access beyond the legitimate array boundaries and setting the return code to -EIO to indicate an input/output error condition.
The operational impact of this vulnerability extends beyond simple memory access violations as it represents a potential vector for privilege escalation or denial of service attacks within kernel space. An attacker who can influence the data structures processed by dtSearch could potentially trigger the out-of-bounds read condition, leading to information leakage from kernel memory regions or causing system crashes through memory corruption. The vulnerability's presence in the JFS subsystem means that any application or process interacting with JFS filesystems could potentially be exploited, particularly in environments where untrusted data is processed through filesystem operations. This aligns with ATT&CK technique T1068 which describes the use of legitimate credentials and system access to escalate privileges or execute malicious code through kernel-level vulnerabilities.
Mitigation strategies for CVE-2023-52602 primarily involve applying the official kernel patch that implements proper bounds checking in the dtSearch function. System administrators should prioritize updating their Linux kernel installations to versions containing this fix, as the vulnerability exists in the core kernel memory management subsystem. Additionally, monitoring for unusual kernel memory access patterns or system crashes may help detect exploitation attempts, though such detection is challenging given the nature of kernel-level vulnerabilities. The fix demonstrates the importance of robust input validation in kernel space, as proper bounds checking prevents the memory corruption that could enable more sophisticated attacks. Organizations maintaining systems with JFS filesystems should ensure comprehensive testing of kernel updates to prevent regression issues while implementing the security patch. The vulnerability also highlights the need for continuous security auditing of kernel subsystems, particularly those handling filesystem operations where memory management errors can have cascading effects on system stability and security posture.