From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Eric Dumazet <edumazet@google.com>,
        Moshe Shemesh <moshe@mellanox.com>,
        Jacob Keller <jacob.e.keller@intel.com>,
        Jiri Pirko <jiri@nvidia.com>,
        Leon Romanovsky <leonro@nvidia.com>,
        Jakub Kicinski <kuba@kernel.org>
Subject: [PATCH 5.15 051/171] devlink: fix netns refcount leak in devlink_nl_cmd_reload()
Date:   Mon, 13 Dec 2021 10:29:26 +0100
Message-Id: <20211213092946.805975522@linuxfoundation.org>
In-Reply-To: <20211213092945.091487407@linuxfoundation.org>
References: <20211213092945.091487407@linuxfoundation.org>
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From: Eric Dumazet <edumazet@google.com>

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>
---
 net/core/devlink.c |   16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

--- a/net/core/devlink.c
+++ b/net/core/devlink.c
@@ -4031,14 +4031,6 @@ static int devlink_nl_cmd_reload(struct
 		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
 			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)