netxen: fix off by one bug in netxen_release_tx_buffer()
Eric Dumazet [Tue, 22 Jan 2013 06:33:05 +0000 (06:33 +0000)]
[ Upstream commit a05948f296ce103989b28a2606e47d2e287c3c89 ]

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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

index 718b274..83538cc 100644 (file)
@@ -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,
index 22b399a..7ee9c74 100644 (file)
@@ -1956,10 +1956,12 @@ 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;