CVE-2024-43913 in Linux
Summary
by MITRE • 08/26/2024
In the Linux kernel, the following vulnerability has been resolved:
nvme: apple: fix device reference counting
Drivers must call nvme_uninit_ctrl after a successful nvme_init_ctrl. Split the allocation side out to make the error handling boundary easier to navigate. The apple driver had been doing this wrong, leaking the controller device memory on a tagset failure.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 12/13/2024
The vulnerability described in CVE-2024-43913 represents a critical resource management issue within the Linux kernel's NVMe subsystem, specifically affecting Apple hardware implementations. This flaw resides in the device reference counting mechanism that governs how controller devices are allocated and deallocated within the NVMe driver framework. The issue stems from improper error handling practices during the initialization process, where the apple-specific NVMe driver fails to properly clean up allocated resources when initialization encounters failures. The vulnerability manifests when the nvme_init_ctrl function successfully initializes a controller but subsequent operations such as tagset allocation fail, leaving controller device memory in an inconsistent state. This improper resource management creates a memory leak that can accumulate over time, potentially leading to system instability and performance degradation.
The technical flaw involves a fundamental violation of proper resource management protocols within the kernel's device driver architecture. The apple NVMe driver implementation incorrectly handles the sequence of operations during controller initialization, failing to call the necessary nvme_uninit_ctrl function when nvme_init_ctrl succeeds but subsequent initialization steps fail. This pattern directly contravenes standard kernel development practices and security guidelines that mandate proper resource cleanup regardless of initialization success or failure states. The error handling boundary becomes problematic when the driver splits the allocation process into separate phases but fails to implement comprehensive cleanup routines for each phase. This specific implementation error creates a scenario where controller device memory remains allocated even when the initialization process ultimately fails, leading to resource exhaustion over extended periods of operation.
The operational impact of this vulnerability extends beyond simple memory leaks to potentially compromise system stability and performance across devices utilizing Apple's NVMe hardware implementations. When the tagset allocation fails during controller initialization, the improperly managed memory allocation can cause progressive resource consumption that may eventually lead to system slowdowns or even complete system crashes. The vulnerability affects systems running Linux kernels that include the apple NVMe driver, particularly those with Apple hardware that relies on NVMe storage controllers. Attackers could potentially exploit this flaw by repeatedly triggering initialization failures, accelerating memory consumption and potentially causing denial of service conditions. The impact is particularly concerning in server environments or systems with high I/O workloads where NVMe controller initialization occurs frequently.
Mitigation strategies for CVE-2024-43913 require immediate kernel updates that implement proper error handling boundaries and resource cleanup routines within the apple NVMe driver. System administrators should prioritize applying the latest kernel patches that address this specific reference counting issue, ensuring that nvme_uninit_ctrl is called appropriately after successful nvme_init_ctrl operations. The fix involves restructuring the allocation process to maintain clear error handling boundaries, making it easier to navigate and ensuring proper cleanup regardless of initialization success or failure. Organizations should implement monitoring systems to track memory usage patterns and identify potential resource exhaustion conditions that may indicate this vulnerability's exploitation. Security teams should also consider implementing automated patch management processes to ensure all systems utilizing Apple NVMe hardware receive timely updates. This vulnerability aligns with CWE-404, which addresses improper resource management, and may be categorized under ATT&CK technique T1499 for resource hijacking, where system resources are consumed through improper memory management practices.