devlink: fix netns refcount leak in devlink_nl_cmd_reload()

commit 4dbb0dad8e63fcd0b5a117c2861d2abe7ff5f186 upstream.

While preparing my patch series adding netns refcount tracking,
I spotted bugs in devlink_nl_cmd_reload()

Some error paths forgot to release a refcount on a netns.

To fix this, we can reduce the scope of get_net()/put_net()
section around the call to devlink_reload().

Fixes: ccdf07219da6 ("devlink: Add reload action option to devlink reload command")
Fixes: dc64cc7c6310 ("devlink: Add devlink reload limit option")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Moshe Shemesh <moshe@mellanox.com>
Cc: Jacob Keller <jacob.e.keller@intel.com>
Cc: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Link: https://lore.kernel.org/r/20211205192822.1741045-1-eric.dumazet@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/core/devlink.c b/net/core/devlink.c
index a856ae401ea5c1da2025120973246ef368ac2faf..6931713e363fd0aaa835b00acd3e035111ad3036 100644 (file)
--- a/net/core/devlink.c
+++ b/net/core/devlink.c
@@ -4031,14 +4031,6 @@ static int devlink_nl_cmd_reload(struct sk_buff *skb, struct genl_info *info)
                return err;
        }
 
-       if (info->attrs[DEVLINK_ATTR_NETNS_PID] ||
-           info->attrs[DEVLINK_ATTR_NETNS_FD] ||
-           info->attrs[DEVLINK_ATTR_NETNS_ID]) {
-               dest_net = devlink_netns_get(skb, info);
-               if (IS_ERR(dest_net))
-                       return PTR_ERR(dest_net);
-       }
-
        if (info->attrs[DEVLINK_ATTR_RELOAD_ACTION])
                action = nla_get_u8(info->attrs[DEVLINK_ATTR_RELOAD_ACTION]);
        else
@@ -4081,6 +4073,14 @@ static int devlink_nl_cmd_reload(struct sk_buff *skb, struct genl_info *info)
                        return -EINVAL;
                }
        }
+       if (info->attrs[DEVLINK_ATTR_NETNS_PID] ||
+           info->attrs[DEVLINK_ATTR_NETNS_FD] ||
+           info->attrs[DEVLINK_ATTR_NETNS_ID]) {
+               dest_net = devlink_netns_get(skb, info);
+               if (IS_ERR(dest_net))
+                       return PTR_ERR(dest_net);
+       }
+
        err = devlink_reload(devlink, dest_net, action, limit, &actions_performed, info->extack);
 
        if (dest_net)