[PATCH 5.10 48/83] net: bridge: fix under estimation in br_get_linkxstats_size()

Greg Kroah-Hartman
2021-10-11T13:55:53Z

From: Eric Dumazet <edumazet@google.com>

[ Upstream commit 0854a0513321cf70bea5fa483ebcaa983cc7c62e ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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 bfe6ab1914c8..31b00ba5dcc8 100644
--- a/net/bridge/br_netlink.c
+++ b/net/bridge/br_netlink.c
@@ -1591,6 +1591,7 @@ 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