net: ieee802154: at86rf230: Stop leaking skb's

BugLink: https://bugs.launchpad.net/bugs/1963890
[ Upstream commit e5ce576d45bf72fd0e3dc37eff897bfcc488f6a9 ]

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>
Acked-by: Alexander Aring <aahringo@redhat.com>
Link: https://lore.kernel.org/r/20220125121426.848337-4-miquel.raynal@bootlin.com
Signed-off-by: Stefan Schmidt <stefan@datenfreihafen.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Paolo Pisati <paolo.pisati@canonical.com>

diff --git a/drivers/net/ieee802154/at86rf230.c b/drivers/net/ieee802154/at86rf230.c
index 7d67f41387f5577959839f902128b1777b4b51ee..4f5ef8a9a9a8796db21f270bbb707eb5204e10f1 100644 (file)
--- 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);
 }