CVE-2024-50284 in Linux
Summary
by MITRE • 11/19/2024
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: Fix the missing xa_store error check
xa_store() can fail, it return xa_err(-EINVAL) if the entry cannot be stored in an XArray, or xa_err(-ENOMEM) if memory allocation failed, so check error for xa_store() to fix it.
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Analysis
by VulDB Data Team • 10/02/2025
The vulnerability identified as CVE-2024-50284 resides within the Linux kernel's ksmbd subsystem, which provides SMB/CIFS file sharing capabilities for Linux systems. This flaw represents a critical oversight in error handling mechanisms that could potentially compromise system stability and security. The ksmbd component serves as a kernel-space implementation for SMB protocol support, enabling Linux systems to function as SMB servers for file and printer sharing within network environments.
The technical flaw manifests in the improper handling of return values from the xa_store() function call within the ksmbd codebase. XArray is a kernel data structure designed to efficiently store and retrieve large numbers of entries while maintaining memory efficiency. The xa_store() function, when invoked, can legitimately return error codes indicating either invalid input parameters (xa_err(-EINVAL)) or memory allocation failures (xa_err(-ENOMEM)). However, the vulnerable code failed to implement proper error checking for these return values, creating a potential execution path where errors are silently ignored.
This missing error check creates a significant operational risk as the system may continue executing with corrupted or incomplete data structures. When xa_store() fails due to invalid parameters, the system might proceed with an inconsistent state, potentially leading to memory corruption or unexpected behavior. In cases where memory allocation fails, the absence of proper error handling could result in system instability or denial of service conditions. The vulnerability directly relates to CWE-252, which addresses the issue of missing error checks in software implementations, and aligns with ATT&CK technique T1499.004 for network denial of service attacks that could potentially exploit such memory handling flaws.
The impact of this vulnerability extends beyond simple error handling, as it could potentially enable attackers to manipulate the kernel's memory management subsystem. When the system encounters memory allocation failures, the lack of proper error handling could lead to memory corruption that might be exploitable under certain conditions. The vulnerability represents a classic case of insufficient input validation and error recovery mechanisms that could be leveraged to compromise system integrity. Organizations running Linux systems with ksmbd enabled are particularly at risk, as the SMB service could be targeted to trigger the error conditions that expose this flaw.
Mitigation strategies should focus on implementing immediate code patches that properly check xa_store() return values and handle error conditions appropriately. System administrators should prioritize updating their kernel versions to include the resolved fix, while also implementing monitoring for unusual memory allocation patterns or service disruptions that might indicate exploitation attempts. The fix should ensure that both -EINVAL and -ENOMEM error conditions are properly handled, potentially through graceful degradation of service or appropriate error reporting mechanisms. Security teams should also consider implementing additional network-level controls to monitor SMB traffic for anomalous patterns that might indicate attempts to exploit this vulnerability.