Patch "net: mdio-mux: Don't ignore memory allocation errors" has been added to the 5.13-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    net: mdio-mux: Don't ignore memory allocation errors

to the 5.13-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     net-mdio-mux-don-t-ignore-memory-allocation-errors.patch
and it can be found in the queue-5.13 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 982d76a6d0381e17567278c10ef9fb87b7d6589b
Author: Saravana Kannan <saravanak@xxxxxxxxxx>
Date:   Tue Aug 17 20:38:02 2021 -0700

    net: mdio-mux: Don't ignore memory allocation errors
    
    [ Upstream commit 99d81e942474cc7677d12f673f42a7ea699e2589 ]
    
    If we are seeing memory allocation errors, don't try to continue
    registering child mdiobus devices. It's unlikely they'll succeed.
    
    Fixes: 342fa1964439 ("mdio: mux: make child bus walking more permissive and errors more verbose")
    Signed-off-by: Saravana Kannan <saravanak@xxxxxxxxxx>
    Reviewed-by: Andrew Lunn <andrew@xxxxxxx>
    Acked-by: Marc Zyngier <maz@xxxxxxxxxx>
    Tested-by: Marc Zyngier <maz@xxxxxxxxxx>
    Acked-by: Kevin Hilman <khilman@xxxxxxxxxxxx>
    Tested-by: Kevin Hilman <khilman@xxxxxxxxxxxx>
    Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/net/mdio/mdio-mux.c b/drivers/net/mdio/mdio-mux.c
index 110e4ee85785..d6ed9033339c 100644
--- a/drivers/net/mdio/mdio-mux.c
+++ b/drivers/net/mdio/mdio-mux.c
@@ -82,6 +82,17 @@ out:
 
 static int parent_count;
 
+static void mdio_mux_uninit_children(struct mdio_mux_parent_bus *pb)
+{
+	struct mdio_mux_child_bus *cb = pb->children;
+
+	while (cb) {
+		mdiobus_unregister(cb->mii_bus);
+		mdiobus_free(cb->mii_bus);
+		cb = cb->next;
+	}
+}
+
 int mdio_mux_init(struct device *dev,
 		  struct device_node *mux_node,
 		  int (*switch_fn)(int cur, int desired, void *data),
@@ -144,7 +155,7 @@ int mdio_mux_init(struct device *dev,
 		cb = devm_kzalloc(dev, sizeof(*cb), GFP_KERNEL);
 		if (!cb) {
 			ret_val = -ENOMEM;
-			continue;
+			goto err_loop;
 		}
 		cb->bus_number = v;
 		cb->parent = pb;
@@ -152,8 +163,7 @@ int mdio_mux_init(struct device *dev,
 		cb->mii_bus = mdiobus_alloc();
 		if (!cb->mii_bus) {
 			ret_val = -ENOMEM;
-			devm_kfree(dev, cb);
-			continue;
+			goto err_loop;
 		}
 		cb->mii_bus->priv = cb;
 
@@ -182,6 +192,10 @@ int mdio_mux_init(struct device *dev,
 
 	dev_err(dev, "Error: No acceptable child buses found\n");
 	devm_kfree(dev, pb);
+
+err_loop:
+	mdio_mux_uninit_children(pb);
+	of_node_put(child_bus_node);
 err_pb_kz:
 	put_device(&parent_bus->dev);
 err_parent_bus:
@@ -193,14 +207,8 @@ EXPORT_SYMBOL_GPL(mdio_mux_init);
 void mdio_mux_uninit(void *mux_handle)
 {
 	struct mdio_mux_parent_bus *pb = mux_handle;
-	struct mdio_mux_child_bus *cb = pb->children;
-
-	while (cb) {
-		mdiobus_unregister(cb->mii_bus);
-		mdiobus_free(cb->mii_bus);
-		cb = cb->next;
-	}
 
+	mdio_mux_uninit_children(pb);
 	put_device(&pb->mii_bus->dev);
 }
 EXPORT_SYMBOL_GPL(mdio_mux_uninit);