e100: Fix broken cbs accounting due to missing memset.

commit 70abc8cb90e679d8519721e2761d8366a18212a6 upstream.

Alan Stern noticed that e100 caused slab corruption.
commit 98468efddb101f8a29af974101c17ba513b07be1 changed
the allocation of cbs to use dma pools that don't return zeroed memory,
especially the cb->status field used to track which cb to clean, causing
(the visible) double freeing of skbs and a wrong free cbs count.

Now the cbs are explicitly zeroed at allocation time.

Reported-by: Alan Stern <stern@rowland.harvard.edu>
Tested-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Roger Oksanen <roger.oksanen@cs.helsinki.fi>
Acked-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/net/e100.c b/drivers/net/e100.c
index b372d9595dd8258c26e093ea2ded081fac4c4b80..c786e6a96eae0cffa0a9e0ac88408d0048a0bbcd 100644 (file)
--- a/drivers/net/e100.c
+++ b/drivers/net/e100.c
@@ -1803,6 +1803,7 @@ static int e100_alloc_cbs(struct nic *nic)
                                  &nic->cbs_dma_addr);
        if (!nic->cbs)
                return -ENOMEM;
+       memset(nic->cbs, 0, count * sizeof(struct cb));
 
        for (cb = nic->cbs, i = 0; i < count; cb++, i++) {
                cb->next = (i + 1 < count) ? cb + 1 : nic->cbs;
@@ -1811,7 +1812,6 @@ static int e100_alloc_cbs(struct nic *nic)
                cb->dma_addr = nic->cbs_dma_addr + i * sizeof(struct cb);
                cb->link = cpu_to_le32(nic->cbs_dma_addr +
                        ((i+1) % count) * sizeof(struct cb));
-               cb->skb = NULL;
        }
 
        nic->cb_to_use = nic->cb_to_send = nic->cb_to_clean = nic->cbs;