Fix 3 leaks in macb_alloc() error paths: - Tx buffer allocated but crossing a 4G boundary: Tx leaked. - Rx buffer allocation fails: Tx leaked. - Rx buffer allocated but crossing a 4G boundary: Tx & Rx leaked. This is because our error handling calls macb_free(bp) which in turn frees the buffers stored in bp->queues[0], but nothing has been stored in there. Fix by storing allocated buffers into bp->queues[0] ASAP. Fixes: 78d901897b3c ("net: macb: single dma_alloc_coherent() for DMA descriptors") Cc: stable@vger.kernel.org Signed-off-by: Théo Lebrun --- drivers/net/ethernet/cadence/macb_main.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c index b8234ac4b602..8e5c034dc3a4 100644 --- a/drivers/net/ethernet/cadence/macb_main.c +++ b/drivers/net/ethernet/cadence/macb_main.c @@ -2749,14 +2749,24 @@ static int macb_alloc(struct macb *bp) size = bp->num_queues * macb_tx_ring_size_per_queue(bp); tx = dma_alloc_coherent(dev, size, &tx_dma, GFP_KERNEL); - if (!tx || upper_32_bits(tx_dma) != upper_32_bits(tx_dma + size - 1)) + if (!tx) + goto out_err; + /* Record the buffer so that the error path frees it. */ + bp->queues[0].tx_ring = tx; + bp->queues[0].tx_ring_dma = tx_dma; + if (upper_32_bits(tx_dma) != upper_32_bits(tx_dma + size - 1)) goto out_err; netdev_dbg(bp->netdev, "Allocated %zu bytes for %u TX rings at %08lx (mapped %p)\n", size, bp->num_queues, (unsigned long)tx_dma, tx); size = bp->num_queues * macb_rx_ring_size_per_queue(bp); rx = dma_alloc_coherent(dev, size, &rx_dma, GFP_KERNEL); - if (!rx || upper_32_bits(rx_dma) != upper_32_bits(rx_dma + size - 1)) + if (!rx) + goto out_err; + /* Record the buffer so that the error path frees it. */ + bp->queues[0].rx_ring = rx; + bp->queues[0].rx_ring_dma = rx_dma; + if (upper_32_bits(rx_dma) != upper_32_bits(rx_dma + size - 1)) goto out_err; netdev_dbg(bp->netdev, "Allocated %zu bytes for %u RX rings at %08lx (mapped %p)\n", size, bp->num_queues, (unsigned long)rx_dma, rx); --- base-commit: 994db8ab9d90c64dd641b7ead6efe2eaea7a50dc change-id: 20260918-macb-alloc-leak-ef38989605c7 Best regards, -- Théo Lebrun