From: Jiri Pirko jiri@mellanox.com
[ Upstream commit 5a508a254bed9a2e36a5fb96c9065532a6bf1e9c ]
There is a race between driver code that does setup/cleanup of device and devlink reload operation that in some drivers works with the same code. Use after free could we easily obtained by running:
while true; do echo "0000:00:10.0" >/sys/bus/pci/drivers/mlxsw_spectrum2/bind devlink dev reload pci/0000:00:10.0 & echo "0000:00:10.0" >/sys/bus/pci/drivers/mlxsw_spectrum2/unbind done
Fix this by enabling reload only after setup of device is complete and disabling it at the beginning of the cleanup process.
Reported-by: Ido Schimmel idosch@mellanox.com Fixes: 2d8dc5bbf4e7 ("devlink: Add support for reload") 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/mlx4/main.c | 3 ++ drivers/net/ethernet/mellanox/mlxsw/core.c | 6 +++- drivers/net/netdevsim/dev.c | 2 + include/net/devlink.h | 3 ++ net/core/devlink.c | 39 ++++++++++++++++++++++++++++- 5 files changed, 51 insertions(+), 2 deletions(-)
--- a/drivers/net/ethernet/mellanox/mlx4/main.c +++ b/drivers/net/ethernet/mellanox/mlx4/main.c @@ -3982,6 +3982,7 @@ static int mlx4_init_one(struct pci_dev goto err_params_unregister;
devlink_params_publish(devlink); + devlink_reload_enable(devlink); pci_save_state(pdev); return 0;
@@ -4093,6 +4094,8 @@ static void mlx4_remove_one(struct pci_d struct devlink *devlink = priv_to_devlink(priv); int active_vfs = 0;
+ devlink_reload_disable(devlink); + if (mlx4_is_slave(dev)) persist->interface_state |= MLX4_INTERFACE_STATE_NOWAIT;
--- a/drivers/net/ethernet/mellanox/mlxsw/core.c +++ b/drivers/net/ethernet/mellanox/mlxsw/core.c @@ -1128,8 +1128,10 @@ __mlxsw_core_bus_device_register(const s if (err) goto err_thermal_init;
- if (mlxsw_driver->params_register) + if (mlxsw_driver->params_register) { devlink_params_publish(devlink); + devlink_reload_enable(devlink); + }
return 0;
@@ -1191,6 +1193,8 @@ void mlxsw_core_bus_device_unregister(st { struct devlink *devlink = priv_to_devlink(mlxsw_core);
+ if (!reload) + devlink_reload_disable(devlink); if (mlxsw_core->reload_fail) { if (!reload) /* Only the parts that were not de-initialized in the --- a/drivers/net/netdevsim/dev.c +++ b/drivers/net/netdevsim/dev.c @@ -297,6 +297,7 @@ nsim_dev_create(struct nsim_bus_dev *nsi if (err) goto err_debugfs_exit;
+ devlink_reload_enable(devlink); return nsim_dev;
err_debugfs_exit: @@ -314,6 +315,7 @@ static void nsim_dev_destroy(struct nsim { struct devlink *devlink = priv_to_devlink(nsim_dev);
+ devlink_reload_disable(devlink); nsim_bpf_dev_exit(nsim_dev); nsim_dev_debugfs_exit(nsim_dev); devlink_unregister(devlink); --- a/include/net/devlink.h +++ b/include/net/devlink.h @@ -35,6 +35,7 @@ struct devlink { struct device *dev; possible_net_t _net; struct mutex lock; + u8 reload_enabled:1; char priv[0] __aligned(NETDEV_ALIGN); };
@@ -594,6 +595,8 @@ struct ib_device; struct devlink *devlink_alloc(const struct devlink_ops *ops, size_t priv_size); int devlink_register(struct devlink *devlink, struct device *dev); void devlink_unregister(struct devlink *devlink); +void devlink_reload_enable(struct devlink *devlink); +void devlink_reload_disable(struct devlink *devlink); void devlink_free(struct devlink *devlink); int devlink_port_register(struct devlink *devlink, struct devlink_port *devlink_port, --- a/net/core/devlink.c +++ b/net/core/devlink.c @@ -2677,7 +2677,7 @@ static int devlink_nl_cmd_reload(struct struct devlink *devlink = info->user_ptr[0]; int err;
- if (!devlink->ops->reload) + if (!devlink->ops->reload || !devlink->reload_enabled) return -EOPNOTSUPP;
err = devlink_resources_validate(devlink, NULL, info); @@ -5559,6 +5559,8 @@ EXPORT_SYMBOL_GPL(devlink_register); void devlink_unregister(struct devlink *devlink) { mutex_lock(&devlink_mutex); + WARN_ON(devlink_reload_supported(devlink) && + devlink->reload_enabled); devlink_notify(devlink, DEVLINK_CMD_DEL); list_del(&devlink->list); mutex_unlock(&devlink_mutex); @@ -5566,6 +5568,41 @@ void devlink_unregister(struct devlink * EXPORT_SYMBOL_GPL(devlink_unregister);
/** + * devlink_reload_enable - Enable reload of devlink instance + * + * @devlink: devlink + * + * Should be called at end of device initialization + * process when reload operation is supported. + */ +void devlink_reload_enable(struct devlink *devlink) +{ + mutex_lock(&devlink_mutex); + devlink->reload_enabled = true; + mutex_unlock(&devlink_mutex); +} +EXPORT_SYMBOL_GPL(devlink_reload_enable); + +/** + * devlink_reload_disable - Disable reload of devlink instance + * + * @devlink: devlink + * + * Should be called at the beginning of device cleanup + * process when reload operation is supported. + */ +void devlink_reload_disable(struct devlink *devlink) +{ + mutex_lock(&devlink_mutex); + /* Mutex is taken which ensures that no reload operation is in + * progress while setting up forbidded flag. + */ + devlink->reload_enabled = false; + mutex_unlock(&devlink_mutex); +} +EXPORT_SYMBOL_GPL(devlink_reload_disable); + +/** * devlink_free - Free devlink instance resources * * @devlink: devlink