From 27f575836cfebbf872dec020428742b10650a955 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Th=C3=A9o=20Lebrun?= Date: Thu, 2 Jul 2026 17:37:02 +0200 Subject: [PATCH] net: macb: drop in-flight Tx SKBs on close MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The MACB driver has since forever leaked the outgoing SKBs that have not yet been marked as completed. They live in queue->tx_skb which gets freed without remorse nor checking. macb_free_consistent() gets called in a few codepaths, but only close will trigger the added expressions. In macb_open() and macb_alloc_consistent() failure cases, queues' tx_skb just got allocated and are empty. Fixes: 89e5785fc8a6 ("[PATCH] Atmel MACB ethernet driver") Cc: stable@vger.kernel.org Reviewed-by: Nicolai Buchwitz Signed-off-by: Théo Lebrun Link: https://patch.msgid.link/20260702-macb-drop-tx-v4-1-1c833eebdbc8@bootlin.com Signed-off-by: Paolo Abeni --- drivers/net/ethernet/cadence/macb_main.c | 21 +++++++++++++++++++-- 1 file changed, 19 insertions(+), 2 deletions(-) diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c index fd282a1700fb..d394f1f43b68 100644 --- a/drivers/net/ethernet/cadence/macb_main.c +++ b/drivers/net/ethernet/cadence/macb_main.c @@ -2668,8 +2668,25 @@ static void macb_free_consistent(struct macb *bp) dma_free_coherent(dev, size, bp->queues[0].rx_ring, bp->queues[0].rx_ring_dma); for (q = 0, queue = bp->queues; q < bp->num_queues; ++q, ++queue) { - kfree(queue->tx_skb); - queue->tx_skb = NULL; + if (queue->tx_skb) { + unsigned int dropped = 0, tail; + + for (tail = queue->tx_tail; tail != queue->tx_head; + tail++) { + if (macb_tx_skb(queue, tail)->skb) + dropped++; + macb_tx_unmap(bp, macb_tx_skb(queue, tail), 0); + } + + queue->stats.tx_dropped += dropped; + bp->dev->stats.tx_dropped += dropped; + + kfree(queue->tx_skb); + queue->tx_skb = NULL; + } + + queue->tx_head = 0; + queue->tx_tail = 0; queue->tx_ring = NULL; queue->rx_ring = NULL; }