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Message-Id: <20241218021940.2967550-1-make_ruc2021@163.com>
Date: Wed, 18 Dec 2024 10:19:40 +0800
From: Ma Ke <make_ruc2021@....com>
To: gregkh@...uxfoundation.org,
stern@...land.harvard.edu,
christophe.jaillet@...adoo.fr,
stanley_chang@...ltek.com,
mka@...omium.org,
oneukum@...e.com,
quic_ugoswami@...cinc.com,
make_ruc2021@....com,
javier.carrasco@...fvision.net,
kay.sievers@...y.org
Cc: linux-usb@...r.kernel.org,
linux-kernel@...r.kernel.org,
stable@...r.kernel.org
Subject: [PATCH v2] usb: fix reference leak in usb_new_device()
When device_add(&udev->dev) failed, calling put_device() to explicitly
release udev->dev. And the routine which calls usb_new_device() does
not call put_device() when an error occurs. As comment of device_add()
says, 'if device_add() succeeds, you should call device_del() when you
want to get rid of it. If device_add() has not succeeded, use only
put_device() to drop the reference count'.
Found by code review.
Cc: stable@...r.kernel.org
Fixes: 9f8b17e643fe ("USB: make usbdevices export their device nodes instead of using a separate class")
Signed-off-by: Ma Ke <make_ruc2021@....com>
---
Changes in v2:
- modified the bug description to make it more clear;
- added the missed part of the patch.
---
drivers/usb/core/hub.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 4b93c0bd1d4b..ddd572312296 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -2651,6 +2651,7 @@ int usb_new_device(struct usb_device *udev)
err = device_add(&udev->dev);
if (err) {
dev_err(&udev->dev, "can't device_add, error %d\n", err);
+ put_device(&udev->dev);
goto fail;
}
@@ -2663,13 +2664,13 @@ int usb_new_device(struct usb_device *udev)
err = sysfs_create_link(&udev->dev.kobj,
&port_dev->dev.kobj, "port");
if (err)
- goto fail;
+ goto out_del_dev;
err = sysfs_create_link(&port_dev->dev.kobj,
&udev->dev.kobj, "device");
if (err) {
sysfs_remove_link(&udev->dev.kobj, "port");
- goto fail;
+ goto out_del_dev;
}
if (!test_and_set_bit(port1, hub->child_usage_bits))
@@ -2683,6 +2684,9 @@ int usb_new_device(struct usb_device *udev)
pm_runtime_put_sync_autosuspend(&udev->dev);
return err;
+out_del_dev:
+ device_del(&udev->dev);
+ put_device(&udev->dev);
fail:
usb_set_device_state(udev, USB_STATE_NOTATTACHED);
pm_runtime_disable(&udev->dev);
--
2.25.1
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