[PATCH 5.14 089/151] net: bridge: fix under estimation in br_get_linkxstats_size()

From: Greg Kroah-Hartman
Date: Mon Oct 11 2021 - 10:08:08 EST


From: Eric Dumazet <edumazet@xxxxxxxxxx>

[ 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@xxxxxxxxxx>
Cc: Vivien Didelot <vivien.didelot@xxxxxxxxx>
Cc: Nikolay Aleksandrov <nikolay@xxxxxxxxxx>
Acked-by: Nikolay Aleksandrov <nikolay@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
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 69c0002f413f..2abfbd4b8a15 100644
--- a/net/bridge/br_netlink.c
+++ b/net/bridge/br_netlink.c
@@ -1658,6 +1658,7 @@ 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