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

[ Upstream commit 8a2f35b9830692f7a616f2f627f943bc748af13a ]

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

Fixes: fb9987d0f748 ("ath9k_htc: Support for AR9271 chipset.")
Signed-off-by: Minsuk Kang <linuxlovemin@yonsei.ac.kr>
Acked-by: Toke Høiland-Jørgensen <toke@toke.dk>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://lore.kernel.org/r/20230104124130.10996-1-linuxlovemin@yonsei.ac.kr
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/net/wireless/ath/ath9k/wmi.c b/drivers/net/wireless/ath/ath9k/wmi.c
index f315c54..19345b8 100644 (file)
--- a/drivers/net/wireless/ath/ath9k/wmi.c
+++ b/drivers/net/wireless/ath/ath9k/wmi.c
@@ -341,6 +341,7 @@ int ath9k_wmi_cmd(struct wmi *wmi, enum wmi_cmd_id cmd_id,
        if (!time_left) {
                ath_dbg(common, WMI, "Timeout waiting for WMI command: %s\n",
                        wmi_cmd_to_name(cmd_id));
+               wmi->last_seq_id = 0;
                mutex_unlock(&wmi->op_mutex);
                return -ETIMEDOUT;
        }