From: Eric Dumazet <edumazet@google.com>
Date: Mon, 4 Oct 2021 18:05:08 -0700
Subject: net: bridge: fix under estimation in br_get_linkxstats_size()
Patch-mainline: v5.15-rc5
Git-commit: 0854a0513321cf70bea5fa483ebcaa983cc7c62e
References: bsc#1176447

Commit de1799667b00 ("net: bridge: add STP xstats")
added an additional nla_reserve_64bit() in br_fill_linkxstats(),
but forgot to update br_get_linkxstats_size() accordingly.

This can trigger the following in rtnl_stats_get()

	WARN_ON(err == -EMSGSIZE);

Fixes: de1799667b00 ("net: bridge: add STP xstats")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Vivien Didelot <vivien.didelot@gmail.com>
Cc: Nikolay Aleksandrov <nikolay@nvidia.com>
Acked-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 net/bridge/br_netlink.c |    1 +
 1 file changed, 1 insertion(+)

--- a/net/bridge/br_netlink.c
+++ b/net/bridge/br_netlink.c
@@ -1558,6 +1558,7 @@ static size_t br_get_linkxstats_size(con
 
 	return numvls * nla_total_size(sizeof(struct bridge_vlan_xstats)) +
 	       nla_total_size_64bit(sizeof(struct br_mcast_stats)) +
+	       (p ? nla_total_size_64bit(sizeof(p->stp_xstats)) : 0) +
 	       nla_total_size(0);
 }