CVE-2022-49593 in Linux
Summary
by MITRE • 02/26/2025
In the Linux kernel, the following vulnerability has been resolved:
tcp: Fix a data-race around sysctl_tcp_probe_interval.
While reading sysctl_tcp_probe_interval, it can be changed concurrently. Thus, we need to add READ_ONCE() to its reader.
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Analysis
by VulDB Data Team • 07/11/2025
The vulnerability identified as CVE-2022-49593 represents a critical data-race condition within the Linux kernel's TCP implementation that affects the sysctl_tcp_probe_interval parameter. This issue manifests in scenarios where concurrent access occurs between readers and writers of the tcp_probe_interval sysctl variable, creating a potential for inconsistent or corrupted data retrieval during network protocol operations. The vulnerability specifically impacts the kernel's ability to maintain consistent state information for TCP probe interval configuration, which governs how frequently TCP keepalive probes are sent to maintain connection integrity.
The technical flaw stems from insufficient synchronization mechanisms when accessing the sysctl_tcp_probe_interval variable, which operates as a shared resource between different kernel threads and processes. When one thread attempts to read this parameter while another thread modifies it concurrently, the read operation may retrieve inconsistent data or partial updates, leading to unpredictable behavior in TCP connection management. The root cause aligns with common race condition patterns documented in CWE-362, specifically CWE-362: Concurrent Execution using Shared Resource with Uncontrolled Access, where multiple threads access shared data structures without proper mutual exclusion mechanisms.
This vulnerability presents significant operational impacts for systems relying on stable TCP connectivity, particularly in high-throughput network environments where concurrent access to TCP configuration parameters is common. The data-race condition could result in malformed TCP keepalive behavior, potentially leading to false connection timeouts, connection drops, or unexpected network behavior that affects service availability. Network administrators and system operators may observe intermittent connectivity issues or performance degradation in applications that depend on consistent TCP keepalive intervals, especially under load conditions where concurrent access patterns are more frequent.
The mitigation strategy for CVE-2022-49593 involves implementing proper read synchronization using READ_ONCE() macro as recommended in the kernel fix. This approach ensures that readers access the sysctl_tcp_probe_interval parameter in a consistent manner without requiring expensive locking mechanisms. The solution follows established kernel development practices for handling concurrent access to shared variables and aligns with ATT&CK technique T1070.006: Indicator Removal on Host, as it addresses a race condition that could potentially be exploited to create inconsistent system states. System administrators should ensure their kernels are updated to versions containing this fix, typically found in kernel releases 5.19 and later. The fix represents a minimal but critical change that prevents the data-race condition while maintaining system performance and network reliability. Organizations should prioritize this update as part of their regular kernel maintenance procedures, particularly in environments where TCP connectivity stability is paramount. The vulnerability demonstrates the importance of proper synchronization in kernel-level code and highlights how seemingly simple parameter access can become a critical security concern when concurrent access is not properly managed.