Subject: [PATCH net 2/2] net: bridge: fix under estimation in br_get_linkxstats_size()

From: Eric Dumazet <[email-masked]>
Date: Mon, 4 Oct 2021 18:05:08 -0700

From: Eric Dumazet <[email-masked]>

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 <[email-masked]>
Cc: Vivien Didelot <[email-masked]>
Cc: Nikolay Aleksandrov <[email-masked]>
---
 net/bridge/br_netlink.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c
index 29b8f6373fb925d48ce876dcda7fccc10539240a..5c6c4305ed235891b2ed5c5a17eb8382f2aec1a0 100644
--- a/net/bridge/br_netlink.c
+++ b/net/bridge/br_netlink.c
@@ -1667,6 +1667,7 @@ static size_t br_get_linkxstats_size(const struct net_device *dev, int attr)
 
 	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);
 }
 
-- 
2.33.0.800.g4c38ced690-goog