CVE-2022-49997 in Linux
Summary
by MITRE • 06/18/2025
In the Linux kernel, the following vulnerability has been resolved:
net: lantiq_xrx200: restore buffer if memory allocation failed
In a situation where memory allocation fails, an invalid buffer address is stored. When this descriptor is used again, the system panics in the build_skb() function when accessing memory.
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Analysis
by VulDB Data Team • 11/30/2025
The vulnerability identified as CVE-2022-49997 resides within the Linux kernel's network subsystem, specifically affecting the lantiq_xrx200 driver implementation. This issue manifests in the handling of memory allocation failures within network packet processing operations, representing a critical flaw that can lead to system instability and potential denial of service conditions. The vulnerability is classified under CWE-476 which denotes a null pointer dereference, though the specific manifestation involves improper buffer handling following allocation failures. The lantiq_xrx200 driver is designed for specific networking hardware platforms and operates at the kernel level where memory management errors can have cascading effects on system stability.
The technical flaw occurs when the network driver encounters a memory allocation failure during packet processing operations. When memory allocation fails, the driver stores an invalid buffer address rather than properly handling the error condition. This improper error handling creates a scenario where subsequent operations attempt to use this invalid memory reference. The vulnerability becomes exploitable when the system attempts to process network packets through the build_skb() function, which performs memory access operations on the corrupted buffer address. This leads to a kernel panic due to invalid memory access patterns that violate the kernel's memory protection mechanisms.
The operational impact of this vulnerability extends beyond simple system crashes, as it can result in complete system downtime and potential data loss in networked environments. Attackers who can trigger memory allocation failures in the network subsystem may be able to cause persistent denial of service conditions, particularly in environments where network traffic is heavy or where the system is under memory pressure. The vulnerability affects systems utilizing lantiq_xrx200 network hardware platforms and can be exploited through network packet injection or by creating memory pressure conditions that force allocation failures. The timing of exploitation is critical as the vulnerability only manifests when specific error conditions occur during active network processing.
Mitigation strategies for CVE-2022-49997 focus primarily on applying the official kernel patches that address the improper buffer handling logic in the lantiq_xrx200 driver. System administrators should prioritize updating to kernel versions that contain the fix, which typically involves proper error handling that prevents invalid buffer addresses from being stored when memory allocation fails. Additional protective measures include implementing network traffic monitoring to detect unusual patterns that may indicate exploitation attempts, configuring memory pressure handling mechanisms to reduce the likelihood of allocation failures, and maintaining robust system monitoring to quickly identify and respond to kernel panics. The fix aligns with ATT&CK technique T1499.004 which covers network denial of service attacks, as the vulnerability can be leveraged to create persistent network availability issues. Organizations should also consider implementing network segmentation and access controls to limit potential exploitation vectors while ensuring comprehensive testing of kernel updates in production environments before deployment.