CVE-2022-49917 in Linux
Summary
by MITRE • 05/01/2025
In the Linux kernel, the following vulnerability has been resolved:
ipvs: fix WARNING in ip_vs_app_net_cleanup()
During the initialization of ip_vs_app_net_init(), if file ip_vs_app fails to be created, the initialization is successful by default. Therefore, the ip_vs_app file doesn't be found during the remove in ip_vs_app_net_cleanup(). It will cause WRNING.
The following is the stack information: name 'ip_vs_app' WARNING: CPU: 1 PID: 9 at fs/proc/generic.c:712 remove_proc_entry+0x389/0x460 Modules linked in: Workqueue: netns cleanup_net RIP: 0010:remove_proc_entry+0x389/0x460 Call Trace: <TASK> ops_exit_list+0x125/0x170 cleanup_net+0x4ea/0xb00 process_one_work+0x9bf/0x1710 worker_thread+0x665/0x1080 kthread+0x2e4/0x3a0 ret_from_fork+0x1f/0x30 </TASK>
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Analysis
by VulDB Data Team • 03/15/2026
The vulnerability CVE-2022-49917 affects the Linux kernel's IP Virtual Server (IPVS) implementation, specifically within the netfilter subsystem that handles virtual server load balancing. This issue occurs during the cleanup phase of IPVS application networking initialization where a warning condition manifests due to improper handling of proc filesystem entries. The problem stems from the ip_vs_app_net_cleanup() function attempting to remove a proc entry that was never successfully created during initialization, creating a mismatch in the kernel's internal state management. This particular vulnerability is classified under CWE-284 Access Control, as it represents a weakness in the kernel's permission and resource management during module initialization and cleanup sequences. The issue demonstrates a classic case of resource leak or improper resource state handling that can lead to system instability and potential information disclosure through kernel warning messages.
The technical flaw manifests when the ip_vs_app_net_init() function attempts to create a proc entry named 'ip_vs_app' but fails to do so successfully. Despite this failure, the initialization process continues and returns successfully, leaving the system in an inconsistent state where the expected proc entry does not exist. Later during the cleanup phase, when ip_vs_app_net_cleanup() is invoked, it attempts to remove the non-existent entry, triggering a WARNING message in the kernel log. The stack trace shows this occurs in fs/proc/generic.c at remove_proc_entry function, specifically at line 712, indicating that the kernel's proc filesystem management code encounters an invalid operation when trying to remove an entry that was never properly registered. The warning originates from the cleanup_net workqueue execution context, suggesting this occurs during network namespace cleanup operations when the kernel attempts to tear down resources associated with the IPVS subsystem.
The operational impact of this vulnerability extends beyond simple warning messages, as it represents a potential indicator of deeper system instability within kernel resource management. While the immediate effect appears to be a WARNING rather than a crash or security breach, such inconsistencies in kernel subsystems can serve as indicators for more serious vulnerabilities or can be exploited in combination with other weaknesses to achieve privilege escalation or denial of service conditions. The vulnerability affects systems running Linux kernels that implement IPVS functionality, particularly those using the netfilter framework for packet filtering and load balancing. From an ATT&CK perspective, this vulnerability aligns with T1068 Valid Accounts and T1499 System Shutdown/Reboot, as improper resource cleanup can lead to system instability and resource exhaustion. The warning condition may also contribute to information disclosure through kernel logs, potentially revealing system configuration details that could be valuable to attackers.
Mitigation strategies for CVE-2022-49917 should focus on ensuring proper error handling and resource state management within the IPVS subsystem. Kernel updates and patches addressing this specific issue should be applied immediately to affected systems, as the vulnerability exists in the kernel's core networking functionality. System administrators should monitor kernel logs for WARNING messages related to ip_vs_app entries and implement proper log analysis procedures to detect potential exploitation attempts. The fix should ensure that if ip_vs_app file creation fails during initialization, the entire initialization process fails appropriately rather than continuing with an inconsistent state. Additionally, organizations should review their network infrastructure configurations to ensure proper handling of IPVS-related services and maintain up-to-date kernel versions with security patches applied. Network security monitoring systems should be configured to alert on anomalous kernel warning patterns that may indicate resource management issues within the kernel's networking subsystem.