ice: fix theoretical out-of-bounds access in ethtool link modes

To map phy types reported by the hardware to ethtool link mode bits,
ice uses two lookup tables (phy_type_low_lkup, phy_type_high_lkup).
The "low" table has 64 elements to cover every possible bit the hardware
may report, but the "high" table has only 13. If the hardware reports a
higher bit in phy_types_high, the driver would access memory beyond the
lookup table's end.

Instead of iterating through all 64 bits of phy_types_{low,high}, use
the sizes of the respective lookup tables.

Fixes: 9136e1f1e5c3 ("ice: refactor PHY type to ethtool link mode")
Signed-off-by: Michal Schmidt <mschmidt@redhat.com>
Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Tested-by: Pucha Himasekhar Reddy <himasekharx.reddy.pucha@intel.com> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

diff --git a/drivers/net/ethernet/intel/ice/ice_ethtool.c b/drivers/net/ethernet/intel/ice/ice_ethtool.c
index a34083567e6ff556b590c20fc28fd9196cb1acd9..bde9bc74f928786d602bc7278dbab96c972f4472 100644 (file)
--- a/drivers/net/ethernet/intel/ice/ice_ethtool.c
+++ b/drivers/net/ethernet/intel/ice/ice_ethtool.c
@@ -1850,14 +1850,14 @@ ice_phy_type_to_ethtool(struct net_device *netdev,
        linkmode_zero(ks->link_modes.supported);
        linkmode_zero(ks->link_modes.advertising);
 
-       for (i = 0; i < BITS_PER_TYPE(u64); i++) {
+       for (i = 0; i < ARRAY_SIZE(phy_type_low_lkup); i++) {
                if (phy_types_low & BIT_ULL(i))
                        ice_linkmode_set_bit(&phy_type_low_lkup[i], ks,
                                             req_speeds, advert_phy_type_lo,
                                             i);
        }
 
-       for (i = 0; i < BITS_PER_TYPE(u64); i++) {
+       for (i = 0; i < ARRAY_SIZE(phy_type_high_lkup); i++) {
                if (phy_types_high & BIT_ULL(i))
                        ice_linkmode_set_bit(&phy_type_high_lkup[i], ks,
                                             req_speeds, advert_phy_type_hi,