wifi: ath9k_htc: Abort software beacon handling if disabled

A malicious USB device can send a WMI_SWBA_EVENTID event from an
ath9k_htc-managed device before beaconing has been enabled. This causes
a device-by-zero error in the driver, leading to either a crash or an
out of bounds read.

Prevent this by aborting the handling in ath9k_htc_swba() if beacons are
not enabled.

Reported-by: Robert Morris <rtm@csail.mit.edu>
Closes: https://lore.kernel.org/r/88967.1743099372@localhost
Fixes: 832f6a18fc2a ("ath9k_htc: Add beacon slots")
Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk>
Link: https://patch.msgid.link/20250402112217.58533-1-toke@toke.dk
Signed-off-by: Jeff Johnson <jeff.johnson@oss.qualcomm.com>

diff --git a/drivers/net/wireless/ath/ath9k/htc_drv_beacon.c b/drivers/net/wireless/ath/ath9k/htc_drv_beacon.c
index 547634f82183d6a7d9965cca27d7ae0e5e9d4b12..81fa7cbad89213cdf65064b93e5bca7743a0e158 100644 (file)
--- a/drivers/net/wireless/ath/ath9k/htc_drv_beacon.c
+++ b/drivers/net/wireless/ath/ath9k/htc_drv_beacon.c
@@ -290,6 +290,9 @@ void ath9k_htc_swba(struct ath9k_htc_priv *priv,
        struct ath_common *common = ath9k_hw_common(priv->ah);
        int slot;
 
+       if (!priv->cur_beacon_conf.enable_beacon)
+               return;
+
        if (swba->beacon_pending != 0) {
                priv->beacon.bmisscnt++;
                if (priv->beacon.bmisscnt > BSTUCK_THRESHOLD) {