[PATCH ath-current v2] wifi: ath11k: cleanup arsta in ath11k_mac_peer_cleanup_all()

[PATCH ath-current v2] wifi: ath11k: cleanup arsta in ath11k_mac_peer_cleanup_all()

[Nicolas Escande]

When mac80211 removes a sta, it calls .sta_state() which in turn calls
ath11k_mac_station_remove(). In that function we clean up both  peers &
arsta related resources.

But when the firmware crashes, ath11k calls ieee80211_restart_hw(), which
assumes that all driver related resources are cleanup up beforehand. This
cleanup is supposedly done by ath11k_mac_peer_cleanup_all() but does not
in fact free arsta->rx_stats / tx_stats.

So lets extract the arsta cleanup from ath11k_mac_station_remove() into a
new ath11k_mac_station_cleanup() and call it from both there and
ath11k_mac_peer_cleanup_all().

This should handle kmemleaks reports like:
	unreferenced object 0xffffff801ae66400 (size 1024):
	  comm "hostapd", pid 1306, jiffies 4295011565
	  hex dump (first 32 bytes):
	    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
	    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
	  backtrace (crc d61c08ec):
	    kmemleak_alloc+0x3c/0x50
	    __kmalloc_cache_noprof+0x2b0/0x3e0
	    ath11k_mac_op_sta_state+0x1dc/0xb10
	    drv_sta_state+0xac/0x6f8
	    sta_info_insert_rcu+0x314/0x5e0
	    sta_info_insert+0x14/0x38
	    ieee80211_add_station+0x10c/0x1a0
	    nl80211_new_station+0x3e8/0x680
	    genl_family_rcv_msg_doit+0xc0/0x120
	    genl_rcv_msg+0x1b4/0x258
	    netlink_rcv_skb+0x4c/0x108
	    genl_rcv+0x38/0x60
	    netlink_unicast+0x190/0x278
	    netlink_sendmsg+0x15c/0x370
	    ____sys_sendmsg+0x120/0x290
	    ___sys_sendmsg+0x70/0xa0

Tested-on: QCN9074 PCI WLAN.HK.2.9.0.1-01977-QCAHKSWPL_SILICONZ-1

Fixes: 9d5f28c1366f ("wifi: ath11k: fix connection failure due to unexpected peer delete")
Signed-off-by: Nicolas Escande <nico.escande@gmail.com>
---
 Note: this problem is in fact older that the referenced commit, but as
 it would need another patch to backport to older kernel and the leak is
 quite minimal & seldom happens, I was hopping to not have to do it.

v2:
	- rebased on ath/master
	- no code change
---
 drivers/net/wireless/ath/ath11k/mac.c | 25 ++++++++++++++++++-------
 1 file changed, 18 insertions(+), 7 deletions(-)

diff --git a/drivers/net/wireless/ath/ath11k/mac.c b/drivers/net/wireless/ath/ath11k/mac.c
index 2d55cdc4d165..ae91b57c8422 100644
--- a/drivers/net/wireless/ath/ath11k/mac.c
+++ b/drivers/net/wireless/ath/ath11k/mac.c
@@ -873,6 +873,22 @@ static int ath11k_mac_set_kickout(struct ath11k_vif *arvif)
 	return 0;
 }
 
+static void ath11k_mac_station_cleanup(struct ieee80211_sta *sta)
+{
+	struct ath11k_sta *arsta;
+
+	if (!sta)
+		return;
+
+	arsta = ath11k_sta_to_arsta(sta);
+
+	kfree(arsta->tx_stats);
+	arsta->tx_stats = NULL;
+
+	kfree(arsta->rx_stats);
+	arsta->rx_stats = NULL;
+}
+
 void ath11k_mac_peer_cleanup_all(struct ath11k *ar)
 {
 	struct ath11k_peer *peer, *tmp;
@@ -885,6 +901,7 @@ void ath11k_mac_peer_cleanup_all(struct ath11k *ar)
 	list_for_each_entry_safe(peer, tmp, &ab->peers, list) {
 		ath11k_peer_rx_tid_cleanup(ar, peer);
 		ath11k_peer_rhash_delete(ab, peer);
+		ath11k_mac_station_cleanup(peer->sta);
 		list_del(&peer->list);
 		kfree(peer);
 	}
@@ -9892,7 +9909,6 @@ static int ath11k_mac_station_remove(struct ath11k *ar,
 {
 	struct ath11k_base *ab = ar->ab;
 	struct ath11k_vif *arvif = ath11k_vif_to_arvif(vif);
-	struct ath11k_sta *arsta = ath11k_sta_to_arsta(sta);
 	int ret;
 
 	if (ab->hw_params.vdev_start_delay &&
@@ -9916,12 +9932,7 @@ static int ath11k_mac_station_remove(struct ath11k *ar,
 			   sta->addr, arvif->vdev_id);
 
 	ath11k_mac_dec_num_stations(arvif, sta);
-
-	kfree(arsta->tx_stats);
-	arsta->tx_stats = NULL;
-
-	kfree(arsta->rx_stats);
-	arsta->rx_stats = NULL;
+	ath11k_mac_station_cleanup(sta);
 
 	return ret;
 }
-- 
2.55.0