From: Huy Nguyen huyn@mellanox.com
commit 3d9c5e023a0dbf3e117bb416cfefd9405bf5af0c upstream.
rtnl_bridge_getlink is protected by rcu lock, so mlx5_eswitch_get_vepa cannot take mutex lock. Two possible issues can happen: 1. User at the same time change vepa mode via RTM_SETLINK command. 2. User at the same time change the switchdev mode via devlink netlink interface.
Case 1 cannot happen because rtnl executes one message in order. Case 2 can happen but we do not expect user to change the switchdev mode when changing vepa. Even if a user does it, so he will read a value which is no longer valid.
Fixes: 8da202b24913 ("net/mlx5: E-Switch, Add support for VEPA in legacy mode.") Signed-off-by: Huy Nguyen huyn@mellanox.com Reviewed-by: Mark Bloch markb@mellanox.com Signed-off-by: Saeed Mahameed saeedm@mellanox.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/net/ethernet/mellanox/mlx5/core/eswitch.c | 14 +++----------- 1 file changed, 3 insertions(+), 11 deletions(-)
--- a/drivers/net/ethernet/mellanox/mlx5/core/eswitch.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/eswitch.c @@ -2449,25 +2449,17 @@ out:
int mlx5_eswitch_get_vepa(struct mlx5_eswitch *esw, u8 *setting) { - int err = 0; - if (!esw) return -EOPNOTSUPP;
if (!ESW_ALLOWED(esw)) return -EPERM;
- mutex_lock(&esw->state_lock); - if (esw->mode != MLX5_ESWITCH_LEGACY) { - err = -EOPNOTSUPP; - goto out; - } + if (esw->mode != MLX5_ESWITCH_LEGACY) + return -EOPNOTSUPP;
*setting = esw->fdb_table.legacy.vepa_uplink_rule ? 1 : 0; - -out: - mutex_unlock(&esw->state_lock); - return err; + return 0; }
int mlx5_eswitch_set_vport_trust(struct mlx5_eswitch *esw,