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%3Ba=su...

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