Commit a05948f2 authored Jan 22, 2013 by Eric Dumazet Committed by David S. Miller Jan 22, 2013

netxen: fix off by one bug in netxen_release_tx_buffer()



Christoph Paasch found netxen could trigger a BUG in its dismantle
phase, in netxen_release_tx_buffer(), using full size TSO packets.

cmd_buf->frag_count includes the skb->data part, so the loop must
start at index 1 instead of 0, or else we can make an out
of bound access to cmd_buff->frag_array[MAX_SKB_FRAGS + 2]

Christoph provided the fixes in netxen_map_tx_skb() function.
In case of a dma mapping error, its better to clear the dma fields
so that we don't try to unmap them again in netxen_release_tx_buffer()

Reported-by: Christoph Paasch <christoph.paasch@uclouvain.be>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Tested-by: Christoph Paasch <christoph.paasch@uclouvain.be>
Cc: Sony Chacko <sony.chacko@qlogic.com>
Cc: Rajesh Borundia <rajesh.borundia@qlogic.com>
Signed-off-by: Christoph Paasch <christoph.paasch@uclouvain.be>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent d721a175

drivers/net/ethernet/qlogic/netxen/netxen_nic_init.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -144,7 +144,7 @@ void netxen_release_tx_buffers(struct netxen_adapter *adapter)
		buffrag->length, PCI_DMA_TODEVICE);
		buffrag->dma = 0ULL;
		}
		for (j = 0; j < cmd_buf->frag_count; j++) {
		for (j = 1; j < cmd_buf->frag_count; j++) {
		buffrag++;
		if (buffrag->dma) {
		pci_unmap_page(adapter->pdev, buffrag->dma,

drivers/net/ethernet/qlogic/netxen/netxen_nic_main.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -1963,10 +1963,12 @@ netxen_map_tx_skb(struct pci_dev *pdev,
		while (--i >= 0) {
		nf = &pbuf->frag_array[i+1];
		pci_unmap_page(pdev, nf->dma, nf->length, PCI_DMA_TODEVICE);
		nf->dma = 0ULL;
		}

		nf = &pbuf->frag_array[0];
		pci_unmap_single(pdev, nf->dma, skb_headlen(skb), PCI_DMA_TODEVICE);
		nf->dma = 0ULL;

		out_err:
		return -ENOMEM;