CVE-2022-50860 in Linux
Summary
by MITRE • 12/30/2025
In the Linux kernel, the following vulnerability has been resolved:
apparmor: Fix memleak in alloc_ns()
After changes in commit a1bd627b46d1 ("apparmor: share profile name on replacement"), the hname member of struct aa_policy is not valid slab object, but a subset of that, it can not be freed by kfree_sensitive(), use aa_policy_destroy() to fix it.
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 04/26/2026
The vulnerability CVE-2022-50860 represents a memory leak in the Linux kernel's AppArmor security module, specifically within the alloc_ns() function. This issue emerged following a significant code modification in commit a1bd627b46d1 titled "apparmor: share profile name on replacement." The fundamental problem lies in how the kernel handles memory allocation and deallocation for AppArmor policy objects, creating a scenario where memory resources become permanently inaccessible due to improper cleanup procedures. The vulnerability affects systems running Linux kernels with AppArmor enabled, potentially leading to gradual memory exhaustion over time.
The technical flaw stems from an improper memory management approach within the AppArmor subsystem's policy handling mechanism. In the modified code, the hname member of the struct aa_policy structure transitions from being a valid slab object to a subset of the original object that cannot be properly freed using the kfree_sensitive() function. This design change creates a memory leak condition where allocated memory remains unrecoverable even after the policy object should be destroyed. The aa_policy_destroy() function, which was designed to properly handle cleanup operations for the complete policy structure, is bypassed in favor of an incorrect memory deallocation method that fails to address the hname member properly.
The operational impact of this vulnerability extends beyond simple memory consumption issues, as it can lead to progressive system instability and performance degradation. When the alloc_ns() function repeatedly executes without proper memory cleanup, it accumulates memory leaks that can eventually consume significant portions of available system RAM. This degradation becomes particularly concerning in long-running systems or environments where AppArmor policies are frequently modified or replaced, as the memory leak compounds over time. The vulnerability can potentially affect system availability if memory exhaustion occurs, forcing system administrators to implement emergency restart procedures to recover allocated resources.
Mitigation strategies for CVE-2022-50860 involve applying the kernel patch that corrects the memory management approach in the AppArmor subsystem. System administrators should prioritize updating to kernel versions that contain the fix, typically those incorporating the specific commit that resolves the issue. The patch ensures that aa_policy_destroy() is properly invoked to handle all members of the policy structure, including the hname component that was previously mishandled. Additionally, monitoring systems for memory usage patterns can help detect early signs of memory leak accumulation, while regular system maintenance and kernel updates remain essential defensive measures. Organizations should also consider implementing automated alerting mechanisms to track memory consumption trends and potential resource exhaustion scenarios that could indicate the presence of this vulnerability or similar memory management issues.
This vulnerability aligns with CWE-401, which specifically addresses improper deallocation of memory, and relates to ATT&CK technique T1490, concerning resource exhaustion attacks. The memory leak represents a classic example of how seemingly minor code changes can introduce significant security implications, particularly in security-critical subsystems like kernel modules. The issue demonstrates the importance of thorough testing and validation when modifying core kernel functionality, especially in security frameworks that handle sensitive system resources. Proper memory management practices and adherence to security standards become crucial when implementing changes that affect kernel-level resource allocation and deallocation mechanisms.