CVE-2024-56546 in Linux
Summary
by MITRE • 12/27/2024
In the Linux kernel, the following vulnerability has been resolved:
drivers: soc: xilinx: add the missing kfree in xlnx_add_cb_for_suspend()
If we fail to allocate memory for cb_data by kmalloc, the memory allocation for eve_data is never freed, add the missing kfree() in the error handling path.
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Analysis
by VulDB Data Team • 12/23/2025
This vulnerability exists in the Linux kernel's Xilinx system-on-chip driver component where a memory leak occurs during suspend/resume operations. The issue is specifically found in the xlnx_add_cb_for_suspend() function which handles callback registration for suspend operations. When the kernel fails to allocate memory for cb_data using kmalloc, the subsequent allocation for eve_data does not have proper error handling to free the previously allocated memory, creating a memory leak condition that can accumulate over time.
The technical flaw represents a classic resource management error where the kernel driver fails to properly handle allocation failures in a sequence of memory operations. The vulnerability stems from inadequate error path handling in the driver's suspend callback management logic, where memory allocated for one data structure is not freed when a subsequent allocation fails. This pattern violates fundamental memory management principles and can lead to progressive memory exhaustion on systems with frequent suspend/resume cycles.
The operational impact of this vulnerability manifests primarily as memory consumption degradation on embedded systems using Xilinx SoC hardware, particularly those with frequent power management operations. Systems running the affected kernel versions may experience gradual memory depletion, potentially leading to system instability, performance degradation, or even system crashes under sustained load conditions. The vulnerability affects devices that rely on Xilinx's hardware abstraction layer for power management operations, including various embedded platforms and automotive applications.
Mitigation strategies should focus on applying the kernel patch that implements proper error handling for the memory allocation sequence. System administrators should prioritize updating to kernel versions containing the fix, particularly on embedded systems with high suspend/resume activity. Additionally, monitoring memory usage patterns and implementing system health checks can help detect potential memory leak accumulation before it impacts system stability. The vulnerability aligns with CWE-401, which addresses improper handling of memory allocation failures, and could be categorized under ATT&CK technique T1490 for resource exhaustion attacks that may be exploited by malicious actors targeting embedded systems with insufficient memory management.
This memory leak represents a subtle but significant issue in embedded kernel drivers where the cumulative effect of small memory leaks can cause substantial operational problems. The fix requires careful attention to proper error path management and ensures that all allocated resources are freed in failure scenarios. System architects should consider the broader implications of such vulnerabilities in embedded environments where memory resources are constrained and where the impact of resource leaks can be more pronounced than in traditional server environments.