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Commit a84e3289 authored by Simon Guinot's avatar Simon Guinot Committed by David S. Miller
Browse files

net: mvneta: fix refilling for Rx DMA buffers 



With the actual code, if a memory allocation error happens while
refilling a Rx descriptor, then the original Rx buffer is both passed
to the networking stack (in a SKB) and let in the Rx ring. This leads
to various kernel oops and crashes.

As a fix, this patch moves Rx descriptor refilling ahead of building
SKB with the associated Rx buffer. In case of a memory allocation
failure, data is dropped and the original DMA buffer is put back into
the Rx ring.

Signed-off-by: default avatarSimon Guinot <simon.guinot@sequanux.org>
Fixes: c5aff182 ("net: mvneta: driver for Marvell Armada 370/XP network unit")
Cc: <stable@vger.kernel.org> # v3.8+
Tested-by: default avatarYoann Sculo <yoann@sculo.fr>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent a7a62685

drivers/net/ethernet/marvell/mvneta.c

+10 −12
Original line number Diff line number Diff line
@@ -1462,7 +1462,7 @@ static int mvneta_rx(struct mvneta_port *pp, int rx_todo, 
		     struct mvneta_rx_queue *rxq)

{

	struct net_device *dev = pp->dev;

	int rx_done, rx_filled;

	int rx_done;

	u32 rcvd_pkts = 0;

	u32 rcvd_bytes = 0;
@@ -1473,7 +1473,6 @@ static int mvneta_rx(struct mvneta_port *pp, int rx_todo, 
		rx_todo = rx_done;



	rx_done = 0;

	rx_filled = 0;



	/* Fairness NAPI loop */

	while (rx_done < rx_todo) {
@@ -1484,7 +1483,6 @@ static int mvneta_rx(struct mvneta_port *pp, int rx_todo, 
		int rx_bytes, err;



		rx_done++;

		rx_filled++;

		rx_status = rx_desc->status;

		rx_bytes = rx_desc->data_size - (ETH_FCS_LEN + MVNETA_MH_SIZE);

		data = (unsigned char *)rx_desc->buf_cookie;
@@ -1524,6 +1522,14 @@ static int mvneta_rx(struct mvneta_port *pp, int rx_todo, 
			continue;

		}



		/* Refill processing */

		err = mvneta_rx_refill(pp, rx_desc);

		if (err) {

			netdev_err(dev, "Linux processing - Can't refill\n");

			rxq->missed++;

			goto err_drop_frame;

		}



		skb = build_skb(data, pp->frag_size > PAGE_SIZE ? 0 : pp->frag_size);

		if (!skb)

			goto err_drop_frame;
@@ -1543,14 +1549,6 @@ static int mvneta_rx(struct mvneta_port *pp, int rx_todo, 
		mvneta_rx_csum(pp, rx_status, skb);



		napi_gro_receive(&pp->napi, skb);



		/* Refill processing */

		err = mvneta_rx_refill(pp, rx_desc);

		if (err) {

			netdev_err(dev, "Linux processing - Can't refill\n");

			rxq->missed++;

			rx_filled--;

		}

	}



	if (rcvd_pkts) {
@@ -1563,7 +1561,7 @@ static int mvneta_rx(struct mvneta_port *pp, int rx_todo, 
	}



	/* Update rxq management counters */

	mvneta_rxq_desc_num_update(pp, rxq, rx_done, rx_filled);

	mvneta_rxq_desc_num_update(pp, rxq, rx_done, rx_done);



	return rx_done;

}