CVE-2022-49819 in Linux
Summary
by MITRE • 05/01/2025
In the Linux kernel, the following vulnerability has been resolved:
octeon_ep: fix potential memory leak in octep_device_setup()
When occur unsupported_dev and mbox init errors, it did not free oct->conf and iounmap() oct->mmio[i].hw_addr. That would trigger memory leak problem.
Add kfree() for oct->conf and iounmap() for oct->mmio[i].hw_addr under
unsupported_dev and mbox init errors to fix the problem.
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Analysis
by VulDB Data Team • 11/10/2025
The vulnerability identified as CVE-2022-49819 resides within the Linux kernel's octeon_ep driver, specifically addressing a memory leak condition that occurs during device setup operations. This flaw manifests in the octep_device_setup() function where proper resource cleanup fails to occur under specific error conditions. The octeon_ep driver interfaces with Cavium Octeon series processors and manages communication through mailbox mechanisms and memory-mapped I/O regions. When the driver encounters unsupported device configurations or mailbox initialization failures, it fails to release allocated kernel memory structures and unmap memory regions that were previously allocated during the setup process.
The technical root cause of this vulnerability stems from inadequate error handling within the device initialization sequence. During normal operation, the driver allocates memory for configuration structures and maps hardware memory regions to provide access to the Octeon processor's registers and communication interfaces. However, when unsupported device detection occurs or mailbox initialization fails, the error path does not execute the necessary cleanup operations. The oct->conf structure contains device configuration data that must be freed to prevent memory leaks, while the oct->mmio[i].hw_addr memory regions require proper unmapping to release kernel virtual memory mappings. This represents a classic resource management flaw where allocated resources are not properly deallocated during error conditions, creating a memory leak that can accumulate over time.
The operational impact of this vulnerability extends beyond simple memory consumption issues, potentially leading to system instability and performance degradation in environments running Linux kernels with affected octeon_ep drivers. Memory leaks can gradually consume available system resources, particularly in systems with high device initialization frequency or those managing multiple Octeon-based devices. The vulnerability is particularly concerning in embedded systems or high-performance computing environments where memory resources are constrained and system reliability is paramount. Attackers could potentially exploit this memory leak to cause denial of service conditions by repeatedly triggering the error path, leading to progressive memory exhaustion that affects system responsiveness and overall stability.
Mitigation strategies for this vulnerability require updating to kernel versions that include the patched octep_device_setup() function, which properly implements kfree() for the oct->conf structure and iounmap() operations for the oct->mmio[i].hw_addr memory regions. System administrators should prioritize kernel updates, particularly in production environments where Octeon-based hardware is deployed. The fix addresses the issue by ensuring that cleanup operations occur regardless of error conditions, following proper resource management principles. This vulnerability aligns with CWE-404, which describes improper resource cleanup or release, and relates to ATT&CK technique T1499.004 for resource exhaustion attacks. Organizations should implement comprehensive patch management procedures to address this memory leak vulnerability and maintain system integrity. The fix demonstrates proper defensive programming practices that should be applied to all kernel drivers handling hardware initialization and resource allocation to prevent similar issues across the Linux kernel ecosystem.