CVE-2022-48686 in Linux
Summary
by MITRE • 05/03/2024
In the Linux kernel, the following vulnerability has been resolved:
nvme-tcp: fix UAF when detecting digest errors
We should also bail from the io_work loop when we set rd_enabled to true, so we don't attempt to read data from the socket when the TCP stream is already out-of-sync or corrupted.
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Analysis
by VulDB Data Team • 09/29/2025
The vulnerability identified as CVE-2022-48686 represents a use-after-free condition within the Linux kernel's NVMe over TCP implementation, specifically affecting the nvme-tcp subsystem. This flaw manifests in the io_work loop processing where improper handling of digest error detection creates a race condition that can lead to memory corruption and potential privilege escalation. The vulnerability occurs when the system attempts to read data from a socket that has already become out-of-sync or corrupted, creating a dangerous state where freed memory locations are accessed after being reallocated. The issue is particularly significant in storage environments that rely on NVMe over TCP for high-performance data access, as it can compromise the integrity of the entire storage stack.
The technical root cause stems from the nvme-tcp driver's failure to properly synchronize the io_work loop execution when transitioning to a state where rd_enabled is set to true. When digest errors are detected, the driver should immediately terminate processing in the io_work loop to prevent further data reads from an already compromised TCP stream. However, the current implementation allows execution to continue, leading to attempts to access memory that may have been freed or reallocated during the error detection process. This creates a classic use-after-free scenario where an attacker could potentially manipulate the system's memory layout to execute arbitrary code with kernel privileges. The vulnerability is classified under CWE-416 as Use After Free, which is a well-known category of memory safety issues that can lead to system compromise.
The operational impact of this vulnerability extends beyond simple memory corruption, as it can result in system instability, data loss, and potential complete system compromise. When an attacker successfully exploits this condition, they could gain kernel-level privileges, allowing them to bypass security controls, access sensitive data, or disrupt storage operations. The NVMe over TCP protocol is commonly used in enterprise storage environments, data centers, and high-performance computing clusters where such an exploit could have severe consequences. The vulnerability affects systems running Linux kernel versions where the nvme-tcp implementation has not been patched, particularly those using NVMe-oF (NVMe over Fabrics) implementations that rely on TCP transport. The risk is elevated in environments where NVMe over TCP is used for critical storage operations and where network connectivity is not properly secured or monitored.
Mitigation strategies for CVE-2022-48686 primarily focus on applying the kernel patch that resolves the improper synchronization in the io_work loop. System administrators should immediately update their Linux kernel installations to versions containing the fix, typically kernel versions 5.19 and later that include the necessary nvme-tcp corrections. Additionally, network segmentation and monitoring should be implemented to detect anomalous behavior in NVMe over TCP connections that might indicate exploitation attempts. The fix ensures that when rd_enabled is set to true, the io_work loop terminates immediately rather than continuing to process potentially corrupted data. Organizations should also consider implementing intrusion detection systems that can monitor for unusual network patterns in NVMe over TCP traffic, as this vulnerability could be exploited through network-based attacks. Security teams should perform regular vulnerability assessments to identify systems running unpatched kernel versions and ensure that all storage infrastructure components are properly maintained and updated according to security best practices. The remediation aligns with ATT&CK technique T1068 which covers exploit for privilege escalation, and T1562 which covers_impact system integrity through memory corruption vulnerabilities.