[PATCH AUTOSEL 6.1 28/60] USB: ULPI: fix memory leak with using debugfs_lookup()

Sasha Levin
2023-03-03T21:46:46Z

From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

[ 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@linux.intel.com>
Link: https://lore.kernel.org/r/20230202153235.2412790-2-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/usb/common/ulpi.c | 14 ++++++--------
1 file changed, 6 insertions(+), 8 deletions(-)

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);

--
2.39.2