[PATCH 5.19 212/365] net: rtnetlink: fix module reference count leak issue in rtnetlink_rcv_msg

[Greg Kroah-Hartman]

From: Zhengchao Shao <shaozhengchao@xxxxxxxxxx>

commit 5b22f62724a0a09e00d301abf5b57b0c12be8a16 upstream.

When bulk delete command is received in the rtnetlink_rcv_msg function,
if bulk delete is not supported, module_put is not called to release
the reference counting. As a result, module reference count is leaked.

Fixes: a6cec0bcd342 ("net: rtnetlink: add bulk delete support flag")
Signed-off-by: Zhengchao Shao <shaozhengchao@xxxxxxxxxx>
Acked-by: Nikolay Aleksandrov <razor@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20220815024629.240367-1-shaozhengchao@xxxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 net/core/rtnetlink.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index ac45328607f7..4b5b15c684ed 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -6070,6 +6070,7 @@ static int rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh,
 	if (kind == RTNL_KIND_DEL && (nlh->nlmsg_flags & NLM_F_BULK) &&
 	    !(flags & RTNL_FLAG_BULK_DEL_SUPPORTED)) {
 		NL_SET_ERR_MSG(extack, "Bulk delete is not supported");
+		module_put(owner);
 		goto err_unlock;
 	}
 
-- 
2.37.2