CVE-2023-53801

Vulnerability

Overview

CVE-2023-53801 describes a memory leak in the Spreadtrum (SPRD) IOMMU driver within the Linux kernel. When a device attaches to an IOMMU domain, the driver allocates a DMA buffer to store the address mapping table. However, this buffer is not released when the IOMMU domain is freed, leading to a gradual loss of memory over time [1].

Exploitation

Context

The vulnerability is triggered through normal kernel operations involving IOMMU domain management. An attacker with the ability to repeatedly attach and detach devices from IOMMU domains—or to create and destroy domains—can cause the leaked DMA buffers to accumulate. No special privileges beyond local access are required, as the bug manifests during routine driver operations [2].

Impact

Over time, the unreleased DMA buffers exhaust system memory, potentially leading to denial of service (DoS) conditions. The system may become unresponsive or crash due to memory starvation. The leak is specific to the SPRD IOMMU implementation and does not affect other IOMMU drivers.

Mitigation

The fix has been applied in the Linux kernel stable tree via commits that ensure the DMA buffer is properly freed when the IOMMU domain is released [1][2]. Users should update to a kernel version containing these patches. No workaround is available other than applying the update.