Commit f4544e53 authored Oct 03, 2020 by Tom Rix Committed by David S. Miller Oct 04, 2020

net: mvneta: fix double free of txq->buf



clang static analysis reports this problem:

drivers/net/ethernet/marvell/mvneta.c:3465:2: warning:
  Attempt to free released memory
        kfree(txq->buf);
        ^~~~~~~~~~~~~~~

When mvneta_txq_sw_init() fails to alloc txq->tso_hdrs,
it frees without poisoning txq->buf.  The error is caught
in the mvneta_setup_txqs() caller which handles the error
by cleaning up all of the txqs with a call to
mvneta_txq_sw_deinit which also frees txq->buf.

Since mvneta_txq_sw_deinit is a general cleaner, all of the
partial cleaning in mvneta_txq_sw_deinit()'s error handling
is not needed.

Fixes: 2adb719d ("net: mvneta: Implement software TSO")
Signed-off-by: Tom Rix <trix@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 580e4273

drivers/net/ethernet/marvell/mvneta.c

+2 −11

Original line number	Diff line number	Diff line
		@@ -3400,24 +3400,15 @@ static int mvneta_txq_sw_init(struct mvneta_port *pp,
		txq->last_desc = txq->size - 1;

		txq->buf = kmalloc_array(txq->size, sizeof(*txq->buf), GFP_KERNEL);
		if (!txq->buf) {
		dma_free_coherent(pp->dev->dev.parent,
		txq->size * MVNETA_DESC_ALIGNED_SIZE,
		txq->descs, txq->descs_phys);
		if (!txq->buf)
		return -ENOMEM;
		}

		/* Allocate DMA buffers for TSO MAC/IP/TCP headers */
		txq->tso_hdrs = dma_alloc_coherent(pp->dev->dev.parent,
		txq->size * TSO_HEADER_SIZE,
		&txq->tso_hdrs_phys, GFP_KERNEL);
		if (!txq->tso_hdrs) {
		kfree(txq->buf);
		dma_free_coherent(pp->dev->dev.parent,
		txq->size * MVNETA_DESC_ALIGNED_SIZE,
		txq->descs, txq->descs_phys);
		if (!txq->tso_hdrs)
		return -ENOMEM;
		}

		/* Setup XPS mapping */
		if (txq_number > 1)

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