CVE-2022-49942

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> wifi: mac80211: Don&amp;#39;t finalize CSA in IBSS mode if state is disconnected<br /> <br /> When we are not connected to a channel, sending channel "switch"<br /> announcement doesn&amp;#39;t make any sense.<br /> <br /> The BSS list is empty in that case. This causes the for loop in<br /> cfg80211_get_bss() to be bypassed, so the function returns NULL<br /> (check line 1424 of net/wireless/scan.c), causing the WARN_ON()<br /> in ieee80211_ibss_csa_beacon() to get triggered (check line 500<br /> of net/mac80211/ibss.c), which was consequently reported on the<br /> syzkaller dashboard.<br /> <br /> Thus, check if we have an existing connection before generating<br /> the CSA beacon in ieee80211_ibss_finish_csa().