Patch "USB: ULPI: fix memory leak with using debugfs_lookup()" has been added to the 6.2-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

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

    USB: ULPI: fix memory leak with using debugfs_lookup()

to the 6.2-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:
     usb-ulpi-fix-memory-leak-with-using-debugfs_lookup.patch
and it can be found in the queue-6.2 subdirectory.

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



commit 01717e06defefff95e50955eabfb2e6ced216edb
Author: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Date:   Thu Feb 2 16:32:24 2023 +0100

    USB: ULPI: fix memory leak with using debugfs_lookup()
    
    [ Upstream commit 8f4d25eba599c4bd4b5ea8ae8752cda480a9d563 ]
    
    When calling debugfs_lookup() the result must have dput() called on it,
    otherwise the memory will leak over time.  To make things simpler, just
    call debugfs_lookup_and_remove() instead which handles all of the logic
    at once.
    
    Acked-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
    Link: https://lore.kernel.org/r/20230202153235.2412790-2-gregkh@xxxxxxxxxxxxxxxxxxx
    Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/usb/common/ulpi.c b/drivers/usb/common/ulpi.c
index d7c8461976ce0..38703781ee2d1 100644
--- a/drivers/usb/common/ulpi.c
+++ b/drivers/usb/common/ulpi.c
@@ -271,7 +271,7 @@ static int ulpi_regs_show(struct seq_file *seq, void *data)
 }
 DEFINE_SHOW_ATTRIBUTE(ulpi_regs);
 
-#define ULPI_ROOT debugfs_lookup(KBUILD_MODNAME, NULL)
+static struct dentry *ulpi_root;
 
 static int ulpi_register(struct device *dev, struct ulpi *ulpi)
 {
@@ -301,7 +301,7 @@ static int ulpi_register(struct device *dev, struct ulpi *ulpi)
 		return ret;
 	}
 
-	root = debugfs_create_dir(dev_name(dev), ULPI_ROOT);
+	root = debugfs_create_dir(dev_name(dev), ulpi_root);
 	debugfs_create_file("regs", 0444, root, ulpi, &ulpi_regs_fops);
 
 	dev_dbg(&ulpi->dev, "registered ULPI PHY: vendor %04x, product %04x\n",
@@ -349,8 +349,7 @@ EXPORT_SYMBOL_GPL(ulpi_register_interface);
  */
 void ulpi_unregister_interface(struct ulpi *ulpi)
 {
-	debugfs_remove_recursive(debugfs_lookup(dev_name(&ulpi->dev),
-						ULPI_ROOT));
+	debugfs_lookup_and_remove(dev_name(&ulpi->dev), ulpi_root);
 	device_unregister(&ulpi->dev);
 }
 EXPORT_SYMBOL_GPL(ulpi_unregister_interface);
@@ -360,12 +359,11 @@ EXPORT_SYMBOL_GPL(ulpi_unregister_interface);
 static int __init ulpi_init(void)
 {
 	int ret;
-	struct dentry *root;
 
-	root = debugfs_create_dir(KBUILD_MODNAME, NULL);
+	ulpi_root = debugfs_create_dir(KBUILD_MODNAME, NULL);
 	ret = bus_register(&ulpi_bus);
 	if (ret)
-		debugfs_remove(root);
+		debugfs_remove(ulpi_root);
 	return ret;
 }
 subsys_initcall(ulpi_init);
@@ -373,7 +371,7 @@ subsys_initcall(ulpi_init);
 static void __exit ulpi_exit(void)
 {
 	bus_unregister(&ulpi_bus);
-	debugfs_remove_recursive(ULPI_ROOT);
+	debugfs_remove(ulpi_root);
 }
 module_exit(ulpi_exit);