Thread (14 messages) 14 messages, 3 authors, 2022-01-27

[wpan v3 3/6] net: ieee802154: at86rf230: Stop leaking skb's

From: Miquel Raynal <miquel.raynal@bootlin.com>
Date: 2022-01-25 12:17:53
Subsystem: ieee 802.15.4 subsystem, networking drivers, the rest · Maintainers: Alexander Aring, Stefan Schmidt, Miquel Raynal, Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds

Upon error the ieee802154_xmit_complete() helper is not called. Only
ieee802154_wake_queue() is called manually. In the Tx case we then leak
the skb structure.

Free the skb structure upon error before returning when appropriate.

As the 'is_tx = 0' cannot be moved in the complete handler because of a
possible race between the delay in switching to STATE_RX_AACK_ON and a
new interrupt, we introduce an intermediate 'was_tx' boolean just for
this purpose.

There is no Fixes tag applying here, many changes have been made on this
area and the issue kind of always existed.

Suggested-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
---
 drivers/net/ieee802154/at86rf230.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)
diff --git a/drivers/net/ieee802154/at86rf230.c b/drivers/net/ieee802154/at86rf230.c
index 7d67f41387f5..4f5ef8a9a9a8 100644
--- a/drivers/net/ieee802154/at86rf230.c
+++ b/drivers/net/ieee802154/at86rf230.c
@@ -100,6 +100,7 @@ struct at86rf230_local {
 	unsigned long cal_timeout;
 	bool is_tx;
 	bool is_tx_from_off;
+	bool was_tx;
 	u8 tx_retry;
 	struct sk_buff *tx_skb;
 	struct at86rf230_state_change tx;
@@ -343,7 +344,11 @@ at86rf230_async_error_recover_complete(void *context)
 	if (ctx->free)
 		kfree(ctx);
 
-	ieee802154_wake_queue(lp->hw);
+	if (lp->was_tx) {
+		lp->was_tx = 0;
+		dev_kfree_skb_any(lp->tx_skb);
+		ieee802154_wake_queue(lp->hw);
+	}
 }
 
 static void
@@ -352,7 +357,11 @@ at86rf230_async_error_recover(void *context)
 	struct at86rf230_state_change *ctx = context;
 	struct at86rf230_local *lp = ctx->lp;
 
-	lp->is_tx = 0;
+	if (lp->is_tx) {
+		lp->was_tx = 1;
+		lp->is_tx = 0;
+	}
+
 	at86rf230_async_state_change(lp, ctx, STATE_RX_AACK_ON,
 				     at86rf230_async_error_recover_complete);
 }
-- 
2.27.0
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