CVE-2022-1247 in Linux
Summary
by MITRE • 08/31/2022
An issue found in linux-kernel that leads to a race condition in rose_connect(). The rose driver uses rose_neigh->use to represent how many objects are using the rose_neigh. When a user wants to delete a rose_route via rose_ioctl(), the rose driver calls rose_del_node() and removes neighbours only if their “count” and “use” are zero.
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Analysis
by VulDB Data Team • 10/10/2022
The vulnerability identified as CVE-2022-1247 represents a critical race condition within the Linux kernel's ROSE (Remote Operations Switching Environment) network driver implementation. This issue specifically manifests in the rose_connect() function where improper synchronization mechanisms lead to inconsistent state management of network neighbors. The ROSE protocol is part of the Linux kernel's AX.25 networking stack designed for packet radio networks and operates under the assumption that neighbor objects maintain consistent usage counts throughout their lifecycle. The flaw stems from the driver's reliance on rose_neigh->use counter to track active references to network neighbors, creating a window where concurrent operations can result in inconsistent state management and potential memory corruption.
The technical exploitation of this race condition occurs when multiple threads or processes attempt to manipulate ROSE network routes simultaneously. The rose_del_node() function, which handles route deletion operations through rose_ioctl() system calls, performs conditional neighbor removal based on both "count" and "use" field values being zero. However, the race condition emerges because the increment and decrement operations on these counters are not atomic or properly synchronized, allowing for scenarios where a neighbor object might be prematurely removed while still being referenced by other active connections or operations. This inconsistency creates opportunities for memory access violations, null pointer dereferences, and potential privilege escalation vectors that can be leveraged by malicious actors to compromise system integrity.
The operational impact of CVE-2022-1247 extends beyond simple denial of service conditions, as the race condition can lead to system crashes, data corruption, and unauthorized privilege escalation within systems running affected kernel versions. Network administrators managing packet radio infrastructure or systems utilizing AX.25 protocols are particularly vulnerable since these networks often operate in mission-critical environments where stability and reliability are paramount. The vulnerability aligns with CWE-362, which specifically addresses Race Conditions in software implementations, and can be mapped to ATT&CK technique T1068, which covers "Exploitation for Privilege Escalation" through kernel-level vulnerabilities. Systems that frequently process network route modifications or maintain high concurrency network operations are most susceptible to exploitation, as the timing requirements for triggering the race condition become more predictable under heavy load conditions.
Mitigation strategies for CVE-2022-1247 require immediate kernel updates from vendors such as Red Hat, SUSE, and Debian, which have released patches addressing the synchronization issues in the ROSE driver implementation. System administrators should prioritize patching affected systems, particularly those operating network infrastructure using AX.25 protocols or ROSE connectivity. Additionally, monitoring network operations for unusual route modification patterns and implementing proper access controls for network management interfaces can help reduce exploitation risk. The vulnerability demonstrates the critical importance of proper synchronization primitives in kernel space operations and highlights the need for comprehensive testing of concurrent access patterns in network driver implementations. Organizations should also consider implementing network segmentation to limit potential impact if exploitation occurs, while maintaining detailed logging of network route modifications to aid in incident response activities.