wifi: ath11k: fix gtk offload status event locking

jira LE-1907
cve CVE-2023-52777
Rebuild_History Non-Buildable kernel-4.18.0-553.16.1.el8_10
commit-author Johan Hovold <[email protected]>
commit 1dea3c0

The ath11k active pdevs are protected by RCU but the gtk offload status
event handling code calling ath11k_mac_get_arvif_by_vdev_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: a16d9b5 ("ath11k: support GTK rekey offload")
	Cc: [email protected]      # 5.18
	Cc: Carl Huang <[email protected]>
	Signed-off-by: Johan Hovold <[email protected]>
	Acked-by: Jeff Johnson <[email protected]>
	Signed-off-by: Kalle Valo <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
(cherry picked from commit 1dea3c0)
	Signed-off-by: Jonathan Maple <[email protected]>

Author: PlaidCat

drivers/net/wireless/ath/ath11k/wmi.c

@@ -8506,12 +8506,13 @@ static void ath11k_wmi_gtk_offload_status_event(struct ath11k_base *ab,
 		return;
 	}
 
+	rcu_read_lock();
+
 	arvif = ath11k_mac_get_arvif_by_vdev_id(ab, ev->vdev_id);
 	if (!arvif) {
 		ath11k_warn(ab, "failed to get arvif for vdev_id:%d\n",
 			    ev->vdev_id);
-		kfree(tb);
-		return;
+		goto exit;
 	}
 
 	ath11k_dbg(ab, ATH11K_DBG_WMI, "wmi gtk offload event refresh_cnt %d\n",
@@ -8528,6 +8529,8 @@ static void ath11k_wmi_gtk_offload_status_event(struct ath11k_base *ab,
 
 	ieee80211_gtk_rekey_notify(arvif->vif, arvif->bssid,
 				   (void *)&replay_ctr_be, GFP_ATOMIC);
+exit:
+	rcu_read_unlock();
 
 	kfree(tb);
 }