CVE-2022-49588 in Linux
Summary
by MITRE • 02/26/2025
In the Linux kernel, the following vulnerability has been resolved:
tcp: Fix data-races around sysctl_tcp_migrate_req.
While reading sysctl_tcp_migrate_req, it can be changed concurrently. Thus, we need to add READ_ONCE() to its readers.
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Analysis
by VulDB Data Team • 02/26/2025
The vulnerability identified as CVE-2022-49588 represents a critical data race condition within the Linux kernel's TCP implementation that specifically affects the sysctl_tcp_migrate_req parameter. This issue arises from insufficient synchronization mechanisms when multiple kernel threads attempt to access and modify the tcp_migrate_req sysctl parameter concurrently. The vulnerability exists in the kernel's networking subsystem where the tcp_migrate_req parameter controls TCP migration behavior during connection handling operations. When multiple processes or kernel threads attempt to read this parameter simultaneously while another thread modifies it, the system can encounter unpredictable behavior due to race conditions in memory access patterns.
The technical flaw manifests as a classic race condition in concurrent programming where the tcp_migrate_req sysctl variable lacks proper atomic access mechanisms during read operations. This parameter controls how TCP connections handle migration scenarios, particularly during connection tracking and state transitions. The kernel's implementation fails to properly protect against simultaneous read and write operations, creating a scenario where readers may observe inconsistent or partially updated values. The vulnerability specifically impacts the kernel's ability to maintain data integrity when multiple concurrent threads attempt to access the sysctl_tcp_migrate_req parameter. This type of race condition falls under CWE-362, which describes concurrent execution using shared data structures without proper synchronization mechanisms. The issue directly relates to improper handling of shared resources in kernel space where multiple execution contexts can access the same memory location without appropriate locking or atomic operations.
The operational impact of this vulnerability extends beyond simple data corruption to potentially compromise system stability and security. When the tcp_migrate_req parameter is accessed concurrently, the kernel may execute incorrect connection migration logic, leading to connection failures, data loss, or potential denial of service conditions. Attackers could potentially exploit this race condition to cause system instability or create conditions that might be leveraged for privilege escalation attacks. The vulnerability affects systems running affected Linux kernel versions where multiple threads or processes access TCP connection parameters simultaneously, particularly in high-concurrency networking environments. This issue is particularly concerning in server environments handling multiple simultaneous TCP connections or in systems implementing advanced TCP features that rely on proper migration handling. The race condition could also potentially be exploited to bypass certain security controls or create conditions that might be leveraged in more sophisticated attacks.
The mitigation strategy for CVE-2022-49588 involves implementing proper read synchronization mechanisms using the READ_ONCE() macro as specified in the kernel fix. This approach ensures that readers of the sysctl_tcp_migrate_req parameter can safely access the value without encountering race conditions during concurrent modifications. The fix aligns with established kernel development practices for handling shared data structures in concurrent environments and follows the ATT&CK framework's mitigation strategies for kernel-level vulnerabilities. The solution addresses the specific issue identified in the Linux kernel's networking subsystem by ensuring atomic access patterns for the tcp_migrate_req parameter. System administrators should apply the relevant kernel updates that contain this fix to ensure proper protection against concurrent access issues. The vulnerability resolution demonstrates the importance of proper synchronization in kernel space operations and highlights the need for comprehensive testing of concurrent access patterns in system-level code. Organizations should verify that their kernel versions include this fix and monitor for similar race conditions in other kernel subsystems that may require similar protective measures.