CVE-2022-49305: drivers: staging: rtl8192u: Fix deadlock in ieee80211_beacons_stop()

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-02-26 · updated 2026-06-17
Weakness: CWE-667

Description

In the Linux kernel, the following vulnerability has been resolved: drivers: staging: rtl8192u: Fix deadlock in ieee80211_beacons_stop() There is a deadlock in ieee80211_beacons_stop(), which is shown below: (Thread 1) | (Thread 2) | ieee80211_send_beacon() ieee80211_beacons_stop() | mod_timer() spin_lock_irqsave() //(1) | (wait a time) ... | ieee80211_send_beacon_cb() del_timer_sync() | spin_lock_irqsave() //(2) (wait timer to stop) | ... We hold ieee->beacon_lock in position (1) of thread 1 and use del_timer_sync() to wait timer to stop, but timer handler also need ieee->beacon_lock in position (2) of thread 2. As a result, ieee80211_beacons_stop() will block forever. This patch extracts del_timer_sync() from the protection of spin_lock_irqsave(), which could let timer handler to obtain the needed lock.

Affected products

Linux kernel: before 4.19.247; from 4.20 before 5.4.198; from 5.5 before 5.10.122; from 5.11 before 5.15.47; from 5.16 before 5.17.15; from 5.18 before 5.18.4 — fixed in 4.19.247, 5.10.122, 5.15.47, 5.17.15, 5.18.4, 5.4.198

How to fix

Upgrade to a fixed version: Linux kernel 4.19.247, 5.10.122, 5.15.47, 5.17.15. Check the vendor advisory for mitigations.

References

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