6.12-stable review patch. If anyone has any objections, please let me know.
------------------
From: Jakub Kicinski <kuba@xxxxxxxxxx>
[ Upstream commit 4a25201aa46ce88e8e31f9ccdec0e4e3dd6bb736 ]
Empty netlink responses from do() are not correct (as opposed to
dump() where not dumping anything is perfectly fine).
We should return an error if the target object does not exist,
in this case if the netdev is down we "hide" the NAPI instances.
Fixes: 27f91aaf49b3 ("netdev-genl: Add netlink framework functions for napi")
Reviewed-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Link: https://patch.msgid.link/20241219032833.1165433-1-kuba@xxxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
net/core/netdev-genl.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/net/core/netdev-genl.c b/net/core/netdev-genl.c
index 7ce22f40db5b..d58270b48cb2 100644
--- a/net/core/netdev-genl.c
+++ b/net/core/netdev-genl.c
@@ -228,8 +228,12 @@ int netdev_nl_napi_get_doit(struct sk_buff *skb, struct genl_info *info)
rcu_read_unlock();
rtnl_unlock();
- if (err)
+ if (err) {
+ goto err_free_msg;
+ } else if (!rsp->len) {
+ err = -ENOENT;
goto err_free_msg;
+ }
return genlmsg_reply(rsp, info);
--
2.39.5
