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 d269a68ce3545d485a506708bb0474af3ad2bdaf..0c53c9295ff630a95c040e3d0b3615974de9a022 100644 (file)
--- a/drivers/net/e100.c
+++ b/drivers/net/e100.c
@@ -1817,6 +1817,7 @@ 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;
@@ -1825,7 +1826,6 @@ 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;