e1000: bounds packet size against buffer size

Otherwise we can write beyond the buffer and corrupt memory.  This is tracked
as CVE-2012-0029.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
This commit is contained in:
Anthony Liguori 2012-01-23 07:30:43 -06:00
parent 520c0d8d27
commit 65f82df0d7

View file

@ -466,6 +466,8 @@ process_tx_desc(E1000State *s, struct e1000_tx_desc *dp)
bytes = split_size;
if (tp->size + bytes > msh)
bytes = msh - tp->size;
bytes = MIN(sizeof(tp->data) - tp->size, bytes);
pci_dma_read(&s->dev, addr, tp->data + tp->size, bytes);
if ((sz = tp->size + bytes) >= hdr && tp->size < hdr)
memmove(tp->header, tp->data, hdr);
@ -481,6 +483,7 @@ process_tx_desc(E1000State *s, struct e1000_tx_desc *dp)
// context descriptor TSE is not set, while data descriptor TSE is set
DBGOUT(TXERR, "TCP segmentaion Error\n");
} else {
split_size = MIN(sizeof(tp->data) - tp->size, split_size);
pci_dma_read(&s->dev, addr, tp->data + tp->size, split_size);
tp->size += split_size;
}