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

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@nxp.com>
---
 net/dsa/switch.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/dsa/switch.c b/net/dsa/switch.c
index 248455145982..5ece05dfd8f2 100644
--- a/net/dsa/switch.c
+++ b/net/dsa/switch.c

@@ -113,11 +113,11 @@ static int dsa_switch_bridge_leave(struct dsa_switch *ds,
 	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);

-- 
2.25.1

Hello:

This patch was applied to netdev/net.git (refs/heads/master):

On Tue, 13 Jul 2021 12:40:21 +0300 you wrote:

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@nxp.com>

[...]

Here is the summary with links:
  - [net] net: dsa: properly check for the bridge_leave methods in dsa_switch_bridge_leave()
    https://git.kernel.org/netdev/net/c/bcb9928a1554

You are awesome, thank you!
--
Deet-doot-dot, I am a bot.
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On 7/13/21 2:40 AM, Vladimir Oltean wrote:

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@nxp.com>

Too late but yes:

Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
-- 
Florian