[PATCH net] inet_diag: Fix error path to cancel the meseage in inet_req_diag_fill()

[Wang Hai]

nlmsg_cancel() needs to be called in the error path of
inet_req_diag_fill to cancel the message.

Fixes: d545caca827b ("net: inet: diag: expose the socket mark to privileged processes.")
Reported-by: Hulk Robot <hulkci@xxxxxxxxxx>
Signed-off-by: Wang Hai <wanghai38@xxxxxxxxxx>
---
 net/ipv4/inet_diag.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/net/ipv4/inet_diag.c b/net/ipv4/inet_diag.c
index 366a4507b5a3..93474b1bea4e 100644
--- a/net/ipv4/inet_diag.c
+++ b/net/ipv4/inet_diag.c
@@ -479,8 +479,10 @@ static int inet_req_diag_fill(struct sock *sk, struct sk_buff *skb,
 	r->idiag_inode	= 0;
 
 	if (net_admin && nla_put_u32(skb, INET_DIAG_MARK,
-				     inet_rsk(reqsk)->ir_mark))
+				     inet_rsk(reqsk)->ir_mark)) {
+		nlmsg_cancel(skb, nlh);
 		return -EMSGSIZE;
+	}
 
 	nlmsg_end(skb, nlh);
 	return 0;
-- 
2.17.1