genetlink: fix error return code in genl_register_family()

Fix to return a negative error code from the idr_alloc() error handling
case instead of 0, as done elsewhere in this function.

Also fix the return value check of idr_alloc() since idr_alloc return
negative errors on failure, not zero.

Fixes: 2ae0f17df1cd ("genetlink: use idr to track families")
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 3 insertions, 1 deletions

diff --git a/net/netlink/genetlink.c b/net/netlink/genetlink.c
index caf04d70ba71..bbd3bff885a1 100644
--- a/net/netlink/genetlink.c
+++ b/net/netlink/genetlink.c
@@ -362,8 +362,10 @@ int genl_register_family(struct genl_family *family)
 
         family->id = idr_alloc(&genl_fam_idr, family,
                                start, end + 1, GFP_KERNEL);
-        if (!family->id)
+        if (family->id < 0) {
+                err = family->id;
                 goto errout_locked;
+        }
 
         err = genl_validate_assign_mc_groups(family);
         if (err)