atl2: Disable unimplemented scatter/gather feature

commit f43bfaeddc79effbf3d0fcb53ca477cca66f3db8 upstream.

atl2 includes NETIF_F_SG in hw_features even though it has no support
for non-linear skbs.  This bug was originally harmless since the
driver does not claim to implement checksum offload and that used to
be a requirement for SG.

Now that SG and checksum offload are independent features, if you
explicitly enable SG *and* use one of the rare protocols that can use
SG without checkusm offload, this potentially leaks sensitive
information (before you notice that it just isn't working).  Therefore
this obscure bug has been designated CVE-2016-2117.

Reported-by: Justin Yackoski <jyackoski@crypto-nite.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Fixes: ec5f06156423 ("net: Kill link between CSUM and SG features.")
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>

diff --git a/drivers/net/ethernet/atheros/atlx/atl2.c b/drivers/net/ethernet/atheros/atlx/atl2.c
index 265ce1b752ed0b169a927f6dad148e694ca4c5a2..96fe542b4acb58fbf5f37bf8d2b3e4a1ff750a64 100644 (file)
--- a/drivers/net/ethernet/atheros/atlx/atl2.c
+++ b/drivers/net/ethernet/atheros/atlx/atl2.c
@@ -1413,7 +1413,7 @@ static int atl2_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 
        err = -EIO;
 
-       netdev->hw_features = NETIF_F_SG | NETIF_F_HW_VLAN_CTAG_RX;
+       netdev->hw_features = NETIF_F_HW_VLAN_CTAG_RX;
        netdev->features |= (NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_CTAG_RX);
 
        /* Init PHY as early as possible due to power saving issue  */