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>
This commit is contained in:
Eric Dumazet 2013-01-22 06:33:05 +00:00 коммит произвёл David S. Miller
Родитель d721a1752b
Коммит a05948f296
2 изменённых файлов: 3 добавлений и 1 удалений

Просмотреть файл

@ -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,

Просмотреть файл

@ -1963,10 +1963,12 @@ unwind:
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;