CVE-2022-49942 wifi: mac80211: Don't finalize CSA in IBSS mode if state is disconnected
A null pointer dereference in the Linux kernel's mac80211 module can cause a system crash when processing channel switch announcements in disconnected IBSS mode.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2022-49942?
CVE-2022-49942 is a medium-severity vulnerability in Linux kernel, published on 18 Jun 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Official 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().
Weakness: CWE-476
Which versions are affected by CVE-2022-49942?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2022-49942?
Apply the vendor's patch.
Is CVE-2022-49942 being exploited?
There is no known exploitation of CVE-2022-49942 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as DEBIAN-CVE-2022-49942, GHSA-8775-7cpf-rm3f, UBUNTU-CVE-2022-49942.