CVE-2023-52799 in Linux
Summary
by MITRE • 05/21/2024
In the Linux kernel, the following vulnerability has been resolved:
jfs: fix array-index-out-of-bounds in dbFindLeaf
Currently while searching for dmtree_t for sufficient free blocks there is an array out of bounds while getting element in tp->dm_stree. To add the required check for out of bound we first need to determine the type of dmtree. Thus added an extra parameter to dbFindLeaf so that the type of tree can be determined and the required check can be applied.
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Analysis
by VulDB Data Team • 03/06/2025
The vulnerability identified as CVE-2023-52799 represents a critical array index out of bounds condition within the Linux kernel's JFS (Journaled File System) implementation. This flaw specifically manifests in the dbFindLeaf function where the system attempts to access elements within the tp->dm_stree array during dmtree_t search operations for locating sufficient free blocks. The issue arises from insufficient bounds checking when accessing array elements, potentially allowing malicious actors to exploit this weakness through carefully crafted file system operations that trigger the vulnerable code path.
The technical implementation of this vulnerability stems from the absence of proper validation when accessing the dm_stree array structure within the JFS subsystem. During the search for adequate free space blocks, the system needs to determine the type of dmtree before applying appropriate bounds checking. The original code lacked this crucial validation step, creating an opportunity for array index manipulation that could lead to memory corruption. This type of vulnerability falls under the CWE-129 category of "Improper Validation of Array Index" and represents a classic example of insufficient bounds checking that can be exploited to achieve arbitrary code execution or system instability.
The operational impact of CVE-2023-52799 extends beyond simple system crashes or memory corruption, as it could potentially enable privilege escalation attacks within the kernel space. When an attacker can manipulate array indices in kernel memory, they may be able to overwrite critical data structures or execute malicious code with kernel privileges. The vulnerability is particularly concerning in environments where JFS is actively used, as it could be exploited through file system operations that trigger the specific code path involving dbFindLeaf. This weakness aligns with ATT&CK technique T1068 which covers 'Exploitation for Privilege Escalation' and represents a classic kernel-level attack vector that could compromise entire systems.
The resolution for this vulnerability involved implementing additional parameter validation within the dbFindLeaf function to properly determine the dmtree type before accessing array elements. This approach follows established security practices for kernel development and memory safety, ensuring that all array accesses are properly validated against known bounds before execution. The fix demonstrates the importance of defensive programming techniques in kernel space, where every array access must be validated against the actual size of the allocated memory structures. System administrators should prioritize applying this kernel patch as soon as possible, particularly in environments where JFS is actively utilized and where the risk of exploitation is elevated due to the potential for privilege escalation through kernel memory corruption attacks.