CVE-2022-49942: wifi: mac80211: Don't finalize CSA in IBSS mode if state is disconnected

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-06-18 · updated 2026-06-17
Weakness: CWE-476

Description

In the Linux kernel, the following vulnerability has been resolved: wifi: mac80211: Don't finalize CSA in IBSS mode if state is disconnected When we are not connected to a channel, sending channel "switch" announcement doesn't make any sense. The BSS list is empty in that case. This causes the for loop in cfg80211_get_bss() to be bypassed, so the function returns NULL (check line 1424 of net/wireless/scan.c), causing the WARN_ON() in ieee80211_ibss_csa_beacon() to get triggered (check line 500 of net/mac80211/ibss.c), which was consequently reported on the syzkaller dashboard. Thus, check if we have an existing connection before generating the CSA beacon in ieee80211_ibss_finish_csa().

Affected products

Linux kernel: from 3.13 before 4.9.328; from 4.10 before 4.14.293; from 4.15 before 4.19.258; from 4.20 before 5.4.213; from 5.5 before 5.10.142; from 5.11 before 5.15.66 — fixed in 4.14.293, 4.19.258, 4.9.328, 5.10.142, 5.15.66, 5.19.8

How to fix

Upgrade to a fixed version: Linux kernel 4.14.293, 4.19.258, 4.9.328, 5.10.142. Check the vendor advisory for mitigations.

References

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