CVE-2026-23040

In the Linux kernel, the following vulnerability has been resolved:

wifi: mac80211_hwsim: fix typo in frequency notification

The NAN notification is for 5745 MHz which corresponds to channel 149 and not 5475 which is not actually a valid channel. This could result in a NULL pointer dereference in cfg80211_next_nan_dw_notif.

The mac80211_hwsim virtual WiFi driver contains an incorrect frequency constant used when generating NAN discovery window notifications on the 5 GHz band that can lead to Null pointer deref. In mac80211_hwsim_nan_dw_start the driver calls ieee80211_get_channel with 5475 MHz when nan_curr_dw_band is NL80211_BAND_5GHZ. That frequency does not correspond to a valid channel in typical wiphy channel tables so ieee80211_get_channel may return NULL. Subsequent NAN notification processing in cfg80211 may then dereference the channel pointer and crash the kernel in cfg80211_next_nan_dw_notif leading to a denial of service. The issue is most relevant in test and simulation environments where mac80211_hwsim is loaded and NAN simulation is enabled. A local attacker with permissions to configure wireless interfaces and NAN behavior can trigger the faulty path by enabling NAN simulation and causing 5 GHz NAN discovery window scheduling.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

To mitigate this issue, prevent module mac80211_hwsim from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.