wifi: ath11k: fix dfs radar event locking

The ath11k active pdevs are protected by RCU but the DFS radar event
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.

Compile tested only.

Fixes: d5c65159f289 ("ath11k: driver for Qualcomm IEEE 802.11ax devices")
Cc: stable@vger.kernel.org      # 5.6
Acked-by: Jeff Johnson <quic_jjohnson@quicinc.com>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://lore.kernel.org/r/20231019153115.26401-3-johan+linaro@kernel.org

diff --git a/drivers/net/wireless/ath/ath11k/wmi.c b/drivers/net/wireless/ath/ath11k/wmi.c
index 4b966aea748ade3b97c52dc027a29aa3f4073036..eac800cebaf4bb1329ff5b26e18893e692b13dcb 100644 (file)
--- a/drivers/net/wireless/ath/ath11k/wmi.c
+++ b/drivers/net/wireless/ath/ath11k/wmi.c
@@ -8336,6 +8336,8 @@ ath11k_wmi_pdev_dfs_radar_detected_event(struct ath11k_base *ab, struct sk_buff
                   ev->detector_id, ev->segment_id, ev->timestamp, ev->is_chirp,
                   ev->freq_offset, ev->sidx);
 
+       rcu_read_lock();
+
        ar = ath11k_mac_get_ar_by_pdev_id(ab, ev->pdev_id);
 
        if (!ar) {
@@ -8353,6 +8355,8 @@ ath11k_wmi_pdev_dfs_radar_detected_event(struct ath11k_base *ab, struct sk_buff
                ieee80211_radar_detected(ar->hw);
 
 exit:
+       rcu_read_unlock();
+
        kfree(tb);
 }