diff options
| author | Lizhi Xu <lizhi.xu@windriver.com> | 2025-10-22 10:40:07 +0800 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2025-10-23 17:27:44 -0700 |
| commit | 420c84c330d1688b8c764479e5738bbdbf0a33de (patch) | |
| tree | 6ca6077f00ee6284b712858109ba335b7108dd48 | |
| parent | a83155cc4ec5dd8c99edb541dc12d3bd8e97eae9 (diff) | |
usbnet: Prevents free active kevent
The root cause of this issue are:
1. When probing the usbnet device, executing usbnet_link_change(dev, 0, 0);
put the kevent work in global workqueue. However, the kevent has not yet
been scheduled when the usbnet device is unregistered. Therefore, executing
free_netdev() results in the "free active object (kevent)" error reported
here.
2. Another factor is that when calling usbnet_disconnect()->unregister_netdev(),
if the usbnet device is up, ndo_stop() is executed to cancel the kevent.
However, because the device is not up, ndo_stop() is not executed.
The solution to this problem is to cancel the kevent before executing
free_netdev().
Fixes: a69e617e533e ("usbnet: Fix linkwatch use-after-free on disconnect")
Reported-by: Sam Sun <samsun1006219@gmail.com>
Closes: https://syzkaller.appspot.com/bug?extid=8bfd7bcc98f7300afb84
Signed-off-by: Lizhi Xu <lizhi.xu@windriver.com>
Link: https://patch.msgid.link/20251022024007.1831898-1-lizhi.xu@windriver.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| -rw-r--r-- | drivers/net/usb/usbnet.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c index bf01f2728531..697cd9d866d3 100644 --- a/drivers/net/usb/usbnet.c +++ b/drivers/net/usb/usbnet.c @@ -1659,6 +1659,8 @@ void usbnet_disconnect (struct usb_interface *intf) net = dev->net; unregister_netdev (net); + cancel_work_sync(&dev->kevent); + while ((urb = usb_get_from_anchor(&dev->deferred))) { dev_kfree_skb(urb->context); kfree(urb->sg); |