wifi: ath9k: Fix potential array-index-out-of-bounds read in ath9k_htc_txstatus()

In the Linux kernel, the following vulnerability has been resolved: wifi: ath9k: Fix potential array-index-out-of-bounds read in ath9k_htc_txstatus() Fix an array-index-out-of-bounds read in ath9k_htc_txstatus(). The bug occurs when txs->cnt, data from a URB provided by a USB device, is bigger than the size of the array txs->txstatus, which is HTC_MAX_TX_STATUS. WARN_ON() already checks it, but there is no bug handling code after the check. Make the function return if that is the case. Found by a modified version of syzkaller. UBSAN: array-index-out-of-bounds in htc_drv_txrx.c index 13 is out of range for type '__wmi_event_txstatus [12]' Call Trace: ath9k_htc_txstatus ath9k_wmi_event_tasklet tasklet_action_common __do_softirq irq_exit_rxu sysvec_apic_timer_interrupt