diff options
| author | Jiri Pirko <jiri@mellanox.com> | 2019-11-09 11:29:46 +0100 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2019-11-09 19:38:36 -0800 |
| commit | 5a508a254bed9a2e36a5fb96c9065532a6bf1e9c (patch) | |
| tree | de6176184a5f1cb07d9875e88f695ab503102935 /net | |
| parent | 0058b0a506e40d9a2c62015fe92eb64a44d78cd9 (diff) | |
| download | linux-5a508a254bed9a2e36a5fb96c9065532a6bf1e9c.tar.bz2 | |
devlink: disallow reload operation during device cleanup
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>
Diffstat (limited to 'net')
| -rw-r--r-- | net/core/devlink.c | 39 |
1 files changed, 38 insertions, 1 deletions
diff --git a/net/core/devlink.c b/net/core/devlink.c index f80151eeaf51..7d64660a72fc 100644 --- a/net/core/devlink.c +++ b/net/core/devlink.c @@ -2699,7 +2699,7 @@ static int devlink_nl_cmd_reload(struct sk_buff *skb, struct genl_info *info) struct devlink *devlink = info->user_ptr[0]; int err; - if (!devlink_reload_supported(devlink)) + if (!devlink_reload_supported(devlink) || !devlink->reload_enabled) return -EOPNOTSUPP; err = devlink_resources_validate(devlink, NULL, info); @@ -6196,6 +6196,8 @@ 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); @@ -6203,6 +6205,41 @@ void devlink_unregister(struct devlink *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 |