Patch "mlxsw: spectrum_router: Fix NULL pointer deref" has been added to the 4.9-stable tree

Patch "mlxsw: spectrum_router: Fix NULL pointer deref" has been added to the 4.9-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    mlxsw: spectrum_router: Fix NULL pointer deref

to the 4.9-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     mlxsw-spectrum_router-fix-null-pointer-deref.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From foo@baz Sat Jan 13 10:51:19 CET 2018
From: Ido Schimmel <idosch@mellanox.com>
Date: Mon, 25 Dec 2017 08:57:35 +0100
Subject: mlxsw: spectrum_router: Fix NULL pointer deref

From: Ido Schimmel <idosch@mellanox.com>


[ Upstream commit 8764a8267b128405cf383157d5e9a4a3735d2409 ]

When we remove the neighbour associated with a nexthop we should always
refuse to write the nexthop to the adjacency table. Regardless if it is
already present in the table or not.

Otherwise, we risk dereferencing the NULL pointer that was set instead
of the neighbour.

Fixes: a7ff87acd995 ("mlxsw: spectrum_router: Implement next-hop routing")
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reported-by: Alexander Petrovskiy <alexpe@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
@@ -1328,9 +1328,9 @@ set_trap:
 static void __mlxsw_sp_nexthop_neigh_update(struct mlxsw_sp_nexthop *nh,
 					    bool removing)
 {
-	if (!removing && !nh->should_offload)
+	if (!removing)
 		nh->should_offload = 1;
-	else if (removing && nh->offloaded)
+	else
 		nh->should_offload = 0;
 	nh->update = 1;
 }


Patches currently in stable-queue which might be from idosch@mellanox.com are

queue-4.9/mlxsw-spectrum_router-fix-null-pointer-deref.patch