From: Eric Dumazet <edumazet@google.com>
Date: Tue, 5 Oct 2021 01:05:08 +0000 (-0700)
Subject: net: bridge: fix under estimation in br_get_linkxstats_size()
X-Git-Tag: v5.15~123^2~17^2
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=0854a0513321cf70bea5fa483ebcaa983cc7c62e;p=platform%2Fkernel%2Flinux-starfive.git

net: bridge: fix under estimation in br_get_linkxstats_size()

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>
---

diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c
index 29b8f63..5c6c430 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);
 }