CVE-2023-53743

Vulnerability

Overview

CVE-2023-53743 describes a memory leak in the Linux kernel's PCI subsystem. The issue arises in the resource coalescing logic: when release_resource() is called to release a PCI resource, it does not actually free the resource or its associated list entry. This results in a memory leak each time coalescing occurs, as the resource list entry remains allocated but unreferenced [1].

Exploitation

Prerequisites

To exploit this vulnerability, an attacker must be able to trigger PCI resource coalescing on the target system. This typically requires local access and the ability to manipulate PCI device configuration, such as through hotplug events or sysfs interfaces. No special privileges beyond normal user access may be necessary, depending on the system's configuration and the availability of relevant device operations.

Impact

An attacker who repeatedly triggers the coalescing operation can exhaust kernel memory, leading to a denial-of-service condition. The leak accumulates over time, potentially causing system instability or crashes as memory resources are depleted. There is no evidence of code execution or privilege escalation from this vulnerability.

Mitigation

The fix is included in the Linux kernel stable tree via commit a08713b9d9031683b83b3ecf12bad40a1ca35211 [1]. Users should update their kernel to a version containing this patch. No workarounds are documented; the only reliable mitigation is applying the kernel update.