CVE-2013-4148 QEMU 1.0 integer conversion in
virtio_net_load()@hw/net/virtio-net.c
Deals with loading a corrupted savevm image.
> n->mac_table.in_use = qemu_get_be32(f);
in_use is int so it can get negative when assigned 32bit unsigned value.
> /* MAC_TABLE_ENTRIES may be different from the saved image */
> if (n->mac_table.in_use <= MAC_TABLE_ENTRIES) {
passing this check ^^^
> qemu_get_buffer(f, n->mac_table.macs,
> n->mac_table.in_use * ETH_ALEN);
with good in_use value, "n->mac_table.in_use * ETH_ALEN" can get
positive and bigger than mac_table.macs. For example 0x81000000
satisfies this condition when ETH_ALEN is 6.
Fix it by making the value unsigned.
For consistency, change first_multi as well.
Note: all call sites were audited to confirm that
making them unsigned didn't cause any issues:
it turns out we actually never do math on them,
so it's easy to validate because both values are
always <= MAC_TABLE_ENTRIES.
Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
71f7fe48e1