CVE-2026-98824: wifi: mac80211: validate TX status rate metadata

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

wifi: mac80211: validate TX status rate metadata

minstrelhttxstatus() converts the HT/VHT rate reported in a TX status into a group and rate index and uses those to index the minstrelht rate tables. The existing validation only checked that an entry was present and had tries recorded; it did not check that the reported MCS, spatial stream count and bandwidth are representable by the tables, so malformed metadata passed to minstrelhtgetstats() or minstrelhtrigetstats() could be used as an out-of-bounds index.

Validate the rate metadata in the common TX status path instead of only in minstrelht, since the values are used by more than rate control. The legacy ieee80211txrate array and the rateinfo based entries are sanitized in ieee80211txstatusext() and ieee80211txrateupdate() before any consumer runs: an entry that does not describe a valid rate for its encoding is dropped. minstrelht keeps the checks that depend on its own tables, i.e. the supported number of spatial streams, the MCS group size and the supported bandwidths.

This does not take away the driver's responsibility to report sane values, it only prevents a single bad report from corrupting mac80211 state. No WARNON() is added: with paniconwarn a driver bug would otherwise turn into a denial of service.