CVE-2024-47712 in Linux
Summary
by MITRE • 10/21/2024
In the Linux kernel, the following vulnerability has been resolved:
wifi: wilc1000: fix potential RCU dereference issue in wilc_parse_join_bss_param
In the `wilc_parse_join_bss_param` function, the TSF field of the `ies` structure is accessed after the RCU read-side critical section is unlocked. According to RCU usage rules, this is illegal. Reusing this pointer can lead to unpredictable behavior, including accessing memory that has been updated or causing use-after-free issues.
This possible bug was identified using a static analysis tool developed by myself, specifically designed to detect RCU-related issues.
To address this, the TSF value is now stored in a local variable `ies_tsf` before the RCU lock is released. The `param->tsf_lo` field is then assigned using this local variable, ensuring that the TSF value is safely accessed.
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Analysis
by VulDB Data Team • 01/19/2026
The vulnerability identified in CVE-2024-47712 affects the Linux kernel's wilc1000 wireless driver component, specifically within the wilc_parse_join_bss_param function where a potential RCU (Read-Copy-Update) dereference issue exists. This flaw represents a critical concurrency problem that can lead to memory safety violations and unpredictable system behavior. The wilc1000 driver is responsible for managing Wi-Fi connectivity in certain wireless chipsets, making this vulnerability particularly concerning for embedded systems and devices that rely on wireless communication. The issue stems from improper handling of RCU-protected data structures during wireless network association processes, where timing-sensitive operations must maintain strict data consistency guarantees.
The technical flaw manifests when the TSF (Timing Synchronization Function) field from the ies structure is accessed after the RCU read-side critical section has been unlocked. This violates fundamental RCU usage principles where pointers obtained within an RCU critical section must not be accessed outside of that protected context. The static analysis tool used to identify this issue employs specialized heuristics designed to detect RCU-related memory safety problems, demonstrating the sophistication required to uncover such subtle concurrency bugs in kernel code. According to CWE-362, this vulnerability aligns with a concurrency flaw where improper synchronization leads to data races and memory corruption issues. The flaw essentially creates a window where a pointer reference becomes invalid, potentially causing use-after-free conditions or accessing freed memory locations that have been reallocated for other purposes.
The operational impact of this vulnerability extends beyond simple memory corruption, as it can lead to system instability, unexpected crashes, or even potential privilege escalation scenarios in certain configurations. When wireless network association processes are interrupted or when multiple threads attempt to access the same RCU-protected data simultaneously, the system may exhibit unpredictable behavior including kernel oops, system panics, or denial of service conditions. This is particularly problematic in embedded devices, IoT systems, or mobile platforms where wireless connectivity is essential for normal operation. The vulnerability affects any system running the Linux kernel with the wilc1000 driver enabled, making it a widespread concern across various hardware platforms that utilize this wireless chipset. From an ATT&CK perspective, this vulnerability could be leveraged by adversaries to achieve privilege escalation or persistent access through kernel memory corruption techniques, though the direct attack surface is limited to wireless network association scenarios.
The fix implemented addresses the core issue by storing the TSF value in a local variable named ies_tsf before releasing the RCU lock, ensuring that all necessary data is safely copied before the critical section ends. This approach follows established RCU best practices by eliminating the need to access RCU-protected data outside of its protected context. The solution prevents potential use-after-free scenarios by ensuring that param->tsf_lo field assignment occurs with data that has been safely extracted from the RCU-protected structure. This remediation technique aligns with standard kernel development practices for handling RCU-protected data and demonstrates the importance of proper synchronization in kernel space programming. The fix maintains the original functionality while ensuring memory safety through careful data handling and proper timing of pointer access operations. The mitigation strategy represents a conservative approach that prioritizes correctness over performance, which is appropriate for kernel-level security fixes where stability and predictability are paramount concerns.