[PATCH 5.13 132/156] net: dsa: properly check for the bridge_leave methods in dsa_switch_bridge_leave()

From: Greg Kroah-Hartman
Date: Thu Jul 22 2021 - 12:52:58 EST


From: Vladimir Oltean <vladimir.oltean@xxxxxxx>

commit bcb9928a155444dbd212473e60241ca0a7f641e1 upstream.

This was not caught because there is no switch driver which implements
the .port_bridge_join but not .port_bridge_leave method, but it should
nonetheless be fixed, as in certain conditions (driver development) it
might lead to NULL pointer dereference.

Fixes: f66a6a69f97a ("net: dsa: permit cross-chip bridging between all trees in the system")
Signed-off-by: Vladimir Oltean <vladimir.oltean@xxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/dsa/switch.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/net/dsa/switch.c
+++ b/net/dsa/switch.c
@@ -110,11 +110,11 @@ static int dsa_switch_bridge_leave(struc
int err, port;

if (dst->index == info->tree_index && ds->index == info->sw_index &&
- ds->ops->port_bridge_join)
+ ds->ops->port_bridge_leave)
ds->ops->port_bridge_leave(ds, info->port, info->br);

if ((dst->index != info->tree_index || ds->index != info->sw_index) &&
- ds->ops->crosschip_bridge_join)
+ ds->ops->crosschip_bridge_leave)
ds->ops->crosschip_bridge_leave(ds, info->tree_index,
info->sw_index, info->port,
info->br);