[PATCH net] ice: fix theoretical out-of-bounds access in ethtool link modes

[PATCH net] ice: fix theoretical out-of-bounds access in ethtool link modes

[Michal Schmidt]

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>
---
 drivers/net/ethernet/intel/ice/ice_ethtool.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/intel/ice/ice_ethtool.c b/drivers/net/ethernet/intel/ice/ice_ethtool.c
index a34083567e6f..bde9bc74f928 100644
--- 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,
-- 
2.41.0

Re: [PATCH net] ice: fix theoretical out-of-bounds access in ethtool link modes

[Przemek Kitszel]

On 11/30/23 17:58, Michal Schmidt wrote:
> 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>
> ---
>   drivers/net/ethernet/intel/ice/ice_ethtool.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/ethernet/intel/ice/ice_ethtool.c b/drivers/net/ethernet/intel/ice/ice_ethtool.c
> index a34083567e6f..bde9bc74f928 100644
> --- 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,

I guess that that "HW reported" number really goes through the FW in
some way, so one could indeed spoil that in some way,
what makes sense to target it at -net.

Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>

Re: [PATCH net] ice: fix theoretical out-of-bounds access in ethtool link modes

[Simon Horman]

On Fri, Dec 01, 2023 at 08:33:36AM +0100, Przemek Kitszel wrote:
> On 11/30/23 17:58, Michal Schmidt wrote:
> > 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>
> > ---
> >   drivers/net/ethernet/intel/ice/ice_ethtool.c | 4 ++--
> >   1 file changed, 2 insertions(+), 2 deletions(-)
> > 
> > diff --git a/drivers/net/ethernet/intel/ice/ice_ethtool.c b/drivers/net/ethernet/intel/ice/ice_ethtool.c
> > index a34083567e6f..bde9bc74f928 100644
> > --- 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,
> 
> I guess that that "HW reported" number really goes through the FW in
> some way, so one could indeed spoil that in some way,
> what makes sense to target it at -net.
> 
> Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>

Reviewed-by: Simon Horman <horms@kernel.org>

RE: [Intel-wired-lan] [PATCH net] ice: fix theoretical out-of-bounds access in ethtool link modes

[Pucha, HimasekharX Reddy]

> -----Original Message-----
> From: Intel-wired-lan <intel-wired-lan-bounces@osuosl.org> On Behalf Of Michal Schmidt
> Sent: Thursday, November 30, 2023 10:28 PM
> To: netdev@vger.kernel.org
> Cc: Nguyen, Anthony L <anthony.l.nguyen@intel.com>; Greenwalt, Paul <paul.greenwalt@intel.com>; intel-wired-lan@lists.osuosl.org; Brandeburg, Jesse <jesse.brandeburg@intel.com>
> Subject: [Intel-wired-lan] [PATCH net] 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>
> ---
>  drivers/net/ethernet/intel/ice/ice_ethtool.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>

Tested-by: Pucha Himasekhar Reddy <himasekharx.reddy.pucha@intel.com> (A Contingent worker at Intel)