[PATCH v2] wilc1000: Fix use of void pointer as a wrong struct type

[PATCH v2] wilc1000: Fix use of void pointer as a wrong struct type

[Vsevolod Kozlov]

ac_classify() expects a struct sk_buff* as its second argument, which is
a member of struct tx_complete_data. priv happens to be a pointer to
struct tx_complete_data, so passing it directly to ac_classify() leads
to wrong behaviour and occasional panics.

Since there is only one caller of wilc_wlan_txq_add_net_pkt and it
already knows the type behind this pointer, and the structure is already
in the header file, change the function signature to use the real type
instead of void* in order to prevent confusion.

Signed-off-by: Vsevolod Kozlov <zaba@mm.st>
---
v2: change function signature to not use pointer to void at all

 drivers/net/wireless/microchip/wilc1000/netdev.c |  2 +-
 drivers/net/wireless/microchip/wilc1000/wlan.c   | 15 ++++++++-------
 drivers/net/wireless/microchip/wilc1000/wlan.h   |  3 ++-
 3 files changed, 11 insertions(+), 9 deletions(-)

diff --git a/drivers/net/wireless/microchip/wilc1000/netdev.c b/drivers/net/wireless/microchip/wilc1000/netdev.c
index 2a1fbbdd6a4b..0c188310919e 100644
--- a/drivers/net/wireless/microchip/wilc1000/netdev.c
+++ b/drivers/net/wireless/microchip/wilc1000/netdev.c
@@ -737,7 +737,7 @@ netdev_tx_t wilc_mac_xmit(struct sk_buff *skb, struct net_device *ndev)
 
 	vif->netstats.tx_packets++;
 	vif->netstats.tx_bytes += tx_data->size;
-	queue_count = wilc_wlan_txq_add_net_pkt(ndev, (void *)tx_data,
+	queue_count = wilc_wlan_txq_add_net_pkt(ndev, tx_data,
 						tx_data->buff, tx_data->size,
 						wilc_tx_complete);
 
diff --git a/drivers/net/wireless/microchip/wilc1000/wlan.c b/drivers/net/wireless/microchip/wilc1000/wlan.c
index c12f27be9f79..31d51385ba93 100644
--- a/drivers/net/wireless/microchip/wilc1000/wlan.c
+++ b/drivers/net/wireless/microchip/wilc1000/wlan.c
@@ -408,7 +408,8 @@ static inline u8 ac_change(struct wilc *wilc, u8 *ac)
 	return 1;
 }
 
-int wilc_wlan_txq_add_net_pkt(struct net_device *dev, void *priv, u8 *buffer,
+int wilc_wlan_txq_add_net_pkt(struct net_device *dev,
+			      struct tx_complete_data *tx_data, u8 *buffer,
 			      u32 buffer_size,
 			      void (*tx_complete_fn)(void *, int))
 {
@@ -420,27 +421,27 @@ int wilc_wlan_txq_add_net_pkt(struct net_device *dev, void *priv, u8 *buffer,
 	wilc = vif->wilc;
 
 	if (wilc->quit) {
-		tx_complete_fn(priv, 0);
+		tx_complete_fn(tx_data, 0);
 		return 0;
 	}
 
 	tqe = kmalloc(sizeof(*tqe), GFP_ATOMIC);
 
 	if (!tqe) {
-		tx_complete_fn(priv, 0);
+		tx_complete_fn(tx_data, 0);
 		return 0;
 	}
 	tqe->type = WILC_NET_PKT;
 	tqe->buffer = buffer;
 	tqe->buffer_size = buffer_size;
 	tqe->tx_complete_func = tx_complete_fn;
-	tqe->priv = priv;
+	tqe->priv = tx_data;
 	tqe->vif = vif;
 
-	q_num = ac_classify(wilc, priv);
+	q_num = ac_classify(wilc, tx_data->skb);
 	tqe->q_num = q_num;
 	if (ac_change(wilc, &q_num)) {
-		tx_complete_fn(priv, 0);
+		tx_complete_fn(tx_data, 0);
 		kfree(tqe);
 		return 0;
 	}
@@ -451,7 +452,7 @@ int wilc_wlan_txq_add_net_pkt(struct net_device *dev, void *priv, u8 *buffer,
 			tcp_process(dev, tqe);
 		wilc_wlan_txq_add_to_tail(dev, q_num, tqe);
 	} else {
-		tx_complete_fn(priv, 0);
+		tx_complete_fn(tx_data, 0);
 		kfree(tqe);
 	}
 
diff --git a/drivers/net/wireless/microchip/wilc1000/wlan.h b/drivers/net/wireless/microchip/wilc1000/wlan.h
index 3d2104f19819..d55eb6b3a12a 100644
--- a/drivers/net/wireless/microchip/wilc1000/wlan.h
+++ b/drivers/net/wireless/microchip/wilc1000/wlan.h
@@ -399,7 +399,8 @@ int wilc_wlan_firmware_download(struct wilc *wilc, const u8 *buffer,
 				u32 buffer_size);
 int wilc_wlan_start(struct wilc *wilc);
 int wilc_wlan_stop(struct wilc *wilc, struct wilc_vif *vif);
-int wilc_wlan_txq_add_net_pkt(struct net_device *dev, void *priv, u8 *buffer,
+int wilc_wlan_txq_add_net_pkt(struct net_device *dev,
+			      struct tx_complete_data *tx_data, u8 *buffer,
 			      u32 buffer_size,
 			      void (*tx_complete_fn)(void *, int));
 int wilc_wlan_handle_txq(struct wilc *wl, u32 *txq_count);
-- 
2.20.1

Re: [PATCH v2] wilc1000: Fix use of void pointer as a wrong struct type

[Kalle Valo]

Vsevolod Kozlov <zaba@mm.st> wrote:

> ac_classify() expects a struct sk_buff* as its second argument, which is
> a member of struct tx_complete_data. priv happens to be a pointer to
> struct tx_complete_data, so passing it directly to ac_classify() leads
> to wrong behaviour and occasional panics.
> 
> Since there is only one caller of wilc_wlan_txq_add_net_pkt and it
> already knows the type behind this pointer, and the structure is already
> in the header file, change the function signature to use the real type
> instead of void* in order to prevent confusion.
> 
> Signed-off-by: Vsevolod Kozlov <zaba@mm.st>

Patch applied to wireless-drivers-next.git, thanks.

6fe91b69cece wilc1000: Fix use of void pointer as a wrong struct type

-- 
https://patchwork.kernel.org/project/linux-wireless/patch/YCQomJ1mO5BLxYOT@Vsevolods-Mini.lan/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches