[PATCH net] netlink: fix a memory leak on error path

[Chengguang Xu]

In genl_register_family(), when idr_alloc() fails,
we forget to free family->attrbuf.

Note, some callers call genl_unregister_family() to clean up
on error path, it doesn't work because the family is inserted
to the global list in the nearly last step.

Fixes: 2ae0f17df1c ("genetlink: use idr to track families").
Signed-off-by: Chengguang Xu <cgxu519@xxxxxxx>
---
 net/netlink/genetlink.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/netlink/genetlink.c b/net/netlink/genetlink.c
index 25eeb6d2a75a..f0ec068e1d02 100644
--- a/net/netlink/genetlink.c
+++ b/net/netlink/genetlink.c
@@ -366,7 +366,7 @@ int genl_register_family(struct genl_family *family)
 			       start, end + 1, GFP_KERNEL);
 	if (family->id < 0) {
 		err = family->id;
-		goto errout_locked;
+		goto errout_free;
 	}

 	err = genl_validate_assign_mc_groups(family);
@@ -385,6 +385,7 @@ int genl_register_family(struct genl_family *family)

 errout_remove:
 	idr_remove(&genl_fam_idr, family->id);
+errout_free:
 	kfree(family->attrbuf);
 errout_locked:
 	genl_unlock_all();
--
2.20.1