wifi: ath9k: Fix potential stack-out-of-bounds write in ath9k_wmi_rsp_callback()

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

wifi: ath9k: Fix potential stack-out-of-bounds write in ath9k_wmi_rsp_callback()

Fix a stack-out-of-bounds write that occurs in a WMI response callback

function that is called after a timeout occurs in ath9k_wmi_cmd().

The callback writes to wmi->cmd_rsp_buf, a stack-allocated buffer that

could no longer be valid when a timeout occurs. Set wmi->last_seq_id to

0 when a timeout occurred.

Found by a modified version of syzkaller.

BUG: KASAN: stack-out-of-bounds in ath9k_wmi_ctrl_rx

Write of size 4

Call Trace:

memcpy

ath9k_wmi_ctrl_rx

ath9k_htc_rx_msg

ath9k_hif_usb_reg_in_cb

__usb_hcd_giveback_urb

usb_hcd_giveback_urb

dummy_timer

call_timer_fn

run_timer_softirq

__do_softirq

irq_exit_rcu

sysvec_apic_timer_interrupt