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net80211: don't dereference a NULL HTINFO IE if it's presented
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Authored by adrian on Jun 11 2025, 6:19 PM.
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Details

Summary

ieee80211_vht_get_vhtflags() is checking the htinfo IE for the
20/40MHz flag as part of deciding valid channel widths.

However, in the hostapd path, the ASSOC_REQ/REASSOC_REQ path
will parse the IEs, do some HT/VHT setup, then call
ieee80211_ht_updatehtcap_final(). In a HT ASSOC/REASSOC request
there won't be a HTINFO IE, however ieee80211_vht_get_vhtflags()
still checks for it, leading to a panic.

Instead, treat it as if we don't yet know if it's HT40 or not.
I'm not sure if we should do that or have it just do
_RETURN_CHAN_BITS(0).

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rG FreeBSD src repository
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