[PATCH] wifi: ath11k: fix htt pktlog locking

[Johan Hovold]

The ath11k active pdevs are protected by RCU but the htt pktlog handling
code calling ath11k_mac_get_ar_by_pdev_id() was not marked as a
read-side critical section.

Mark the code in question as an RCU read-side critical section to avoid
any potential use-after-free issues.

Fixes: d5c65159f289 ("ath11k: driver for Qualcomm IEEE 802.11ax devices")
Cc: stable@xxxxxxxxxxxxxxx      # 5.6
Signed-off-by: Johan Hovold <johan+linaro@xxxxxxxxxx>
---

Here's one more...

Johan

 drivers/net/wireless/ath/ath11k/dp_rx.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/net/wireless/ath/ath11k/dp_rx.c b/drivers/net/wireless/ath/ath11k/dp_rx.c
index 62bc98852f0f..0acbf53ae991 100644
--- a/drivers/net/wireless/ath/ath11k/dp_rx.c
+++ b/drivers/net/wireless/ath/ath11k/dp_rx.c
@@ -1621,14 +1621,18 @@ static void ath11k_htt_pktlog(struct ath11k_base *ab, struct sk_buff *skb)
 	u8 pdev_id;
 
 	pdev_id = FIELD_GET(HTT_T2H_PPDU_STATS_INFO_PDEV_ID, data->hdr);
+
+	rcu_read_lock();
 	ar = ath11k_mac_get_ar_by_pdev_id(ab, pdev_id);
 	if (!ar) {
 		ath11k_warn(ab, "invalid pdev id %d on htt pktlog\n", pdev_id);
-		return;
+		goto out;
 	}
 
 	trace_ath11k_htt_pktlog(ar, data->payload, hdr->size,
 				ar->ab->pktlog_defs_checksum);
+out:
+	rcu_read_unlock();
 }
 
 static void ath11k_htt_backpressure_event_handler(struct ath11k_base *ab,
-- 
2.41.0