CVE-2022-49315 is a vulnerability identified in the Linux kernel, specifically within the staging driver for the Realtek rtl8192e wireless chipset. The flaw is a deadlock condition occurring in the function rtllib_beacons_stop(). This function attempts to stop beacon transmissions by acquiring a spinlock (ieee->beacon_lock) and then calling del_timer_sync() to wait for a timer to stop. However, the timer handler function, rtllib_send_beacon_cb(), also attempts to acquire the same spinlock. Because del_timer_sync() is called while holding the spinlock, the timer handler cannot proceed to acquire the lock, resulting in a deadlock where rtllib_beacons_stop() blocks indefinitely. The patch resolves this by moving the del_timer_sync() call outside the protection of the spinlock, allowing the timer handler to acquire the lock and complete, thus preventing the deadlock. This vulnerability is a classic concurrency issue involving improper lock handling and timer synchronization in kernel code. It affects Linux kernel versions containing the vulnerable rtl8192e driver code prior to the patch. There are no known exploits in the wild, and no CVSS score has been assigned yet.

The deadlock vulnerability can cause the affected Linux kernel systems to hang or become unresponsive when the rtllib_beacons_stop() function is invoked, which is part of the wireless driver operations for Realtek rtl8192e chipsets. This can lead to denial of service (DoS) conditions on systems using this wireless hardware, potentially disrupting network connectivity and impacting availability. For European organizations relying on Linux servers or embedded devices with this chipset for wireless communication, this could result in operational downtime or degraded service. While this vulnerability does not directly expose confidentiality or integrity risks, the availability impact could be significant in environments where wireless connectivity is critical, such as industrial control systems, telecommunications infrastructure, or enterprise wireless networks. The lack of known exploits reduces immediate risk, but unpatched systems remain vulnerable to accidental or malicious triggering of the deadlock.

European organizations should prioritize updating their Linux kernel to the patched version that addresses CVE-2022-49315. Specifically, they should ensure that the rtl8192e wireless driver is updated to the fixed code where del_timer_sync() is called outside the spinlock protection. For systems where kernel upgrades are not immediately feasible, organizations can consider disabling the affected wireless driver if it is not in use or replacing the hardware with supported chipsets not affected by this issue. Additionally, thorough testing of wireless driver behavior under load and during shutdown sequences can help detect deadlock conditions early. Monitoring system logs for kernel warnings or hangs related to wireless operations can provide early indicators of this vulnerability being triggered. Network segmentation and limiting access to devices running vulnerable kernels can reduce the risk of exploitation or accidental triggering.