From: Lizhi Xu <lizhi.xu@windriver.com> stable inclusion from stable-v6.6.117 commit 9a579d6a39513069d298eee70770bbac8a148565 category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/11499 CVE: CVE-2025-68312 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- [ Upstream commit 420c84c330d1688b8c764479e5738bbdbf0a33de ] 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> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Ziming Du <duziming2@huawei.com> --- drivers/net/usb/usbnet.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c index c4134303d395..5f8606a55dbe 100644 --- a/drivers/net/usb/usbnet.c +++ b/drivers/net/usb/usbnet.c @@ -1649,6 +1649,8 @@ 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); -- 2.43.0