From 271e48ec78bcfed9d6c3f59f78ee51fb2ef42ee2 Mon Sep 17 00:00:00 2001 From: Vladimir Oltean Date: Fri, 8 Sep 2023 16:33:52 +0300 Subject: [PATCH] net: dsa: sja1105: block FDB accesses that are concurrent with a switch reset [ Upstream commit 86899e9e1e29e854b5f6dcc24ba4f75f792c89aa ] Currently, when we add the first sja1105 port to a bridge with vlan_filtering 1, then we sometimes see this output: sja1105 spi2.2: port 4 failed to read back entry for be:79:b4:9e:9e:96 vid 3088: -ENOENT sja1105 spi2.2: Reset switch and programmed static config. Reason: VLAN filtering sja1105 spi2.2: port 0 failed to add be:79:b4:9e:9e:96 vid 0 to fdb: -2 It is because sja1105_fdb_add() runs from the dsa_owq which is no longer serialized with switch resets since it dropped the rtnl_lock() in the blamed commit. Either performing the FDB accesses before the reset, or after the reset, is equally fine, because sja1105_static_fdb_change() backs up those changes in the static config, but FDB access during reset isn't ok. Make sja1105_static_config_reload() take the fdb_lock to fix that. Fixes: 0faf890fc519 ("net: dsa: drop rtnl_lock from dsa_slave_switchdev_event_work") Signed-off-by: Vladimir Oltean Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- drivers/net/dsa/sja1105/sja1105_main.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/net/dsa/sja1105/sja1105_main.c b/drivers/net/dsa/sja1105/sja1105_main.c index 79927191ac623..013976b0af9f1 100644 --- a/drivers/net/dsa/sja1105/sja1105_main.c +++ b/drivers/net/dsa/sja1105/sja1105_main.c @@ -2304,6 +2304,7 @@ int sja1105_static_config_reload(struct sja1105_private *priv, int rc, i; s64 now; + mutex_lock(&priv->fdb_lock); mutex_lock(&priv->mgmt_lock); mac = priv->static_config.tables[BLK_IDX_MAC_CONFIG].entries; @@ -2416,6 +2417,7 @@ int sja1105_static_config_reload(struct sja1105_private *priv, goto out; out: mutex_unlock(&priv->mgmt_lock); + mutex_unlock(&priv->fdb_lock); return rc; }