From: Or Gerlitz <ogerlitz@mellanox.com>

Date: Tue, 13 Mar 2018 21:43:43 +0200

Subject: net/mlx5e: Avoid using the ipv6 stub in the TC offload neigh update

 path

Patch-mainline: v4.16

Git-commit: 423c9db29943cfc43e3a408192e9efa4178af6a1

References: bsc#1046303 FATE#322944

Currently we use the global ipv6_stub var to access the ipv6 global

nd table. This practice gets us to troubles when the stub is only partially

set e.g when ipv6 is loaded under the disabled policy. In this case, as of commit

343d60aada5a ("ipv6: change ipv6_stub_impl.ipv6_dst_lookup to take net argument")

the stub is not null, but stub->nd_tbl is and we crash.

As we can access the ipv6 nd_tbl directly, the fix is just to avoid the

reference through the stub. There is one place in the code where we

issue ipv6 route lookup and keep doing it through the stub, but that

mentioned commit makes sure we get -EAFNOSUPPORT from the stack.

Fixes: 232c001398ae ("net/mlx5e: Add support to neighbour update flow")

Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>

Reviewed-by: Aviv Heller <avivh@mellanox.com>

Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>

---

 drivers/net/ethernet/mellanox/mlx5/core/en_rep.c |    6 +++---

 drivers/net/ethernet/mellanox/mlx5/core/en_tc.c  |    2 +-

 2 files changed, 4 insertions(+), 4 deletions(-)

--- a/drivers/net/ethernet/mellanox/mlx5/core/en_rep.c

+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_rep.c

@@ -235,7 +235,7 @@ void mlx5e_remove_sqs_fwd_rules(struct m

 static void mlx5e_rep_neigh_update_init_interval(struct mlx5e_rep_priv *rpriv)

 {

 #if IS_ENABLED(CONFIG_IPV6)

-	unsigned long ipv6_interval = NEIGH_VAR(&ipv6_stub->nd_tbl->parms,

+	unsigned long ipv6_interval = NEIGH_VAR(&nd_tbl.parms,

 						DELAY_PROBE_TIME);

 #else

 	unsigned long ipv6_interval = ~0UL;

@@ -371,7 +371,7 @@ static int mlx5e_rep_netevent_event(stru

 	case NETEVENT_NEIGH_UPDATE:

 		n = ptr;

 #if IS_ENABLED(CONFIG_IPV6)

-		if (n->tbl != ipv6_stub->nd_tbl && n->tbl != &arp_tbl)

+		if (n->tbl != &nd_tbl && n->tbl != &arp_tbl)

 #else

 		if (n->tbl != &arp_tbl)

 #endif

@@ -419,7 +419,7 @@ static int mlx5e_rep_netevent_event(stru

 		 * done per device delay prob time parameter.

 		 */

 #if IS_ENABLED(CONFIG_IPV6)

-		if (!p->dev || (p->tbl != ipv6_stub->nd_tbl && p->tbl != &arp_tbl))

+		if (!p->dev || (p->tbl != &nd_tbl && p->tbl != &arp_tbl))

 #else

 		if (!p->dev || p->tbl != &arp_tbl)

 #endif

--- a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c

+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c

@@ -484,7 +484,7 @@ void mlx5e_tc_update_neigh_used_value(st

 		tbl = &arp_tbl;

 #if IS_ENABLED(CONFIG_IPV6)

 	else if (m_neigh->family == AF_INET6)

-		tbl = ipv6_stub->nd_tbl;

+		tbl = &nd_tbl;

 #endif

 	else

 		return;