[PATCH net] devlink: fix netns refcount leak in devlink_nl_cmd_reload()

From: Eric Dumazet <redacted>

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 <redacted>
Cc: Moshe Shemesh <redacted>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Jacob Keller <jacob.e.keller@intel.com>
Cc: Jiri Pirko <redacted>
---
 net/core/devlink.c | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/net/core/devlink.c b/net/core/devlink.c
index 5ad72dbfcd0797ae045734b83fbbdc090ae3ff53..c06c9ba6e8c5ea00a3999700a6724a404c1f05f9 100644
--- a/net/core/devlink.c
+++ b/net/core/devlink.c

@@ -4110,14 +4110,6 @@ 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

@@ -4160,6 +4152,14 @@ 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)

-- 
2.34.1.400.ga245620fadb-goog

On Sun, Dec 05, 2021 at 11:28:22AM -0800, Eric Dumazet wrote:

From: Eric Dumazet <redacted>

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 <redacted>
Cc: Moshe Shemesh <redacted>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Jacob Keller <jacob.e.keller@intel.com>
Cc: Jiri Pirko <redacted>
---
 net/core/devlink.c | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

Thanks,
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>

Hello:

This patch was applied to netdev/net.git (master)
by Jakub Kicinski [off-list ref]:

On Sun,  5 Dec 2021 11:28:22 -0800 you wrote:

From: Eric Dumazet <redacted>

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.

[...]

Here is the summary with links:
  - [net] devlink: fix netns refcount leak in devlink_nl_cmd_reload()
    https://git.kernel.org/netdev/net/c/4dbb0dad8e63

You are awesome, thank you!
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