2023-02-02 15:35:39

by Greg Kroah-Hartman

Subject: [PATCH 02/13] USB: ULPI: fix memory leak with using debugfs_lookup()

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.

Cc: Heikki Krogerus <[email protected]>
Cc: [email protected]
Cc: [email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
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 67b780b256a9..a98b2108376a 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);

--
2.39.1

2023-02-03 09:06:02

by Heikki Krogerus

Subject: Re: [PATCH 02/13] USB: ULPI: fix memory leak with using debugfs_lookup()

On Thu, Feb 02, 2023 at 04:32:24PM +0100, Greg Kroah-Hartman wrote:
> 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.
>
> Cc: Heikki Krogerus <[email protected]>
> Cc: [email protected]
> Cc: [email protected]
> Signed-off-by: Greg Kroah-Hartman <[email protected]>

Acked-by: Heikki Krogerus <[email protected]>

> ---
> 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 67b780b256a9..a98b2108376a 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);
>
> --
> 2.39.1

--
heikki