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 | 4 ++ drivers/net/netdevsim/netdev.c | 5 +++ include/net/devlink.h | 3 ++ net/core/devlink.c | 39 ++++++++++++++++++++++++++++- 5 files changed, 53 insertions(+), 1 deletion(-)
--- 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 if (ret) goto err_params_unregister;
+ 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 @@ -1054,6 +1054,8 @@ int mlxsw_core_bus_device_register(const if (err) goto err_driver_init; } + if (!reload) + devlink_reload_enable(devlink);
return 0;
@@ -1088,6 +1090,8 @@ 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/netdev.c +++ b/drivers/net/netdevsim/netdev.c @@ -23,6 +23,7 @@ #include <net/pkt_cls.h> #include <net/rtnetlink.h> #include <net/switchdev.h> +#include <net/devlink.h>
#include "netdevsim.h"
@@ -221,6 +222,8 @@ static int nsim_init(struct net_device * goto err_unreg_dev;
nsim_ipsec_init(ns); + if (ns->devlink) + devlink_reload_enable(ns->devlink);
return 0;
@@ -243,6 +246,8 @@ static void nsim_uninit(struct net_devic { struct netdevsim *ns = netdev_priv(dev);
+ if (ns->devlink) + devlink_reload_disable(ns->devlink); nsim_ipsec_teardown(ns); nsim_devlink_teardown(ns); debugfs_remove_recursive(ns->ddir); --- 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); };
@@ -477,6 +478,8 @@ 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 @@ -2643,7 +2643,7 @@ 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); @@ -3889,6 +3889,8 @@ EXPORT_SYMBOL_GPL(devlink_register); void devlink_unregister(struct devlink *devlink) { mutex_lock(&devlink_mutex); + WARN_ON(devlink->ops->reload && + devlink->reload_enabled); devlink_notify(devlink, DEVLINK_CMD_DEL); list_del(&devlink->list); mutex_unlock(&devlink_mutex); @@ -3896,6 +3898,41 @@ 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