CVE-2022-48783 in Linux
Summary
by MITRE • 07/16/2024
In the Linux kernel, the following vulnerability has been resolved:
net: dsa: lantiq_gswip: fix use after free in gswip_remove()
of_node_put(priv->ds->slave_mii_bus->dev.of_node) should be done before mdiobus_free(priv->ds->slave_mii_bus).
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Analysis
by VulDB Data Team • 08/22/2024
The vulnerability CVE-2022-48783 represents a critical use-after-free condition within the Linux kernel's DSA (Distributed Switch Architecture) subsystem, specifically affecting the Lantiq GSWIP driver implementation. This flaw exists in the gswip_remove() function where improper resource cleanup sequence leads to potential system instability and security risks. The issue manifests when the device driver attempts to release memory resources in an incorrect order during driver removal operations, creating a scenario where a freed memory reference is accessed subsequently.
The technical root cause stems from a violation of proper resource management protocols within the device driver's cleanup routine. According to CWE-416, this vulnerability falls under the category of use-after-free conditions where memory that has been deallocated is still being referenced. The problematic code sequence involves calling mdiobus_free() on the slave MII bus before properly releasing the device node reference through of_node_put(). This improper ordering creates a situation where the device node reference remains valid while the underlying MII bus structure has already been freed, leading to potential memory corruption or privilege escalation opportunities.
The operational impact of this vulnerability extends beyond simple memory corruption, as it can compromise the stability of network operations within systems utilizing Lantiq GSWIP switches. When the driver removal process occurs, typically during system shutdown, module unloading, or hardware hot-plugging scenarios, the improper cleanup sequence can trigger kernel oops, system crashes, or potentially enable malicious actors to exploit the memory corruption for privilege escalation. The vulnerability affects systems running Linux kernel versions where the DSA subsystem is utilized with Lantiq GSWIP switch drivers, particularly those implementing the gswip_remove() function without proper resource ordering.
From an ATT&CK perspective, this vulnerability maps to techniques involving privilege escalation and system stability compromise through kernel-level memory corruption. The vulnerability aligns with T1068 (Exploitation for Privilege Escalation) and T1499 (Endpoint Termination) as it can be leveraged to disrupt system operations or gain elevated privileges. The exploitation requires local access or the ability to trigger driver removal operations, making it relevant to both insider threat scenarios and potential remote exploitation if the system allows arbitrary driver unloading. Organizations implementing network infrastructure using Lantiq switches should prioritize patching this vulnerability as it represents a fundamental flaw in the kernel's device management subsystem.
The recommended mitigation strategy involves applying the kernel patch that corrects the resource cleanup order by ensuring of_node_put() is called before mdiobus_free() in the gswip_remove() function. This fix aligns with best practices for device driver development and memory management within the Linux kernel ecosystem. System administrators should verify their kernel versions and apply the appropriate security patches from their distribution vendors. Additionally, monitoring for kernel oops or system instability patterns during driver removal operations can serve as an early warning indicator of potential exploitation attempts. The fix demonstrates proper adherence to kernel development guidelines and resource management protocols that prevent such use-after-free conditions in device driver cleanup routines.