From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 16D9A34889C; Wed, 3 Dec 2025 16:18:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764778739; cv=none; b=KoTW+0eY1LksLr48gtypKS/xaFwzTOAFkyAAhiCrVh6NetCfr9qQ57t6EkdzS50TABDhokrXd2yLT62iv0OGGY8s4QRDVsBCdmMhjMSmvpVyNYo32Ryn44JN9k/6kWbLKgizakXdhzQnqgqOpUkTNqXs1X8sOQ4YnmKjk6KZu6A= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764778739; c=relaxed/simple; bh=zKmdtIhxz1IAsGsW1Cf4bCYBHOm3Nz9Hu3yRfbjZLY0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=nQJrhU3hu9by0Y8rlJs/U3ANnqJ3nBz59UaFD/dReIm7b7ovGIj59+mqpSYCR9JyH9tXgNPMsUArP746pONrwrhmha2CENKjlVvsOSDK+b1jQahQ0jE3UXFGg/0SLjPeOMk34c6qJWbE+v9lPFr2nUaCBTPBACIAQkcifIDeP9g= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=hRWxqOry; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="hRWxqOry" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 851A1C4CEF5; Wed, 3 Dec 2025 16:18:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1764778738; bh=zKmdtIhxz1IAsGsW1Cf4bCYBHOm3Nz9Hu3yRfbjZLY0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=hRWxqOryv7ilUmzMqSUm4qGLXjHboeoqJQgS5SHZtvLPeQ4OCLsgobO6st6V2j+qY km0/Use4/VCr0DJLwUI9os0N9lkXoFzU16AFvCIJHAg36wn7wz/NYlkf8+su1nVEa6 7YxF/cCLfKpv/WLFGHIlHi9REI7mwTUrdWHfeIlE= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Sam Sun , Lizhi Xu , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.1 045/568] usbnet: Prevents free active kevent Date: Wed, 3 Dec 2025 16:20:47 +0100 Message-ID: <20251203152442.341618329@linuxfoundation.org> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20251203152440.645416925@linuxfoundation.org> References: <20251203152440.645416925@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Lizhi Xu [ 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 Closes: https://syzkaller.appspot.com/bug?extid=8bfd7bcc98f7300afb84 Signed-off-by: Lizhi Xu Link: https://patch.msgid.link/20251022024007.1831898-1-lizhi.xu@windriver.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- 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 a68fead887207..6bdf035e35f56 100644 --- a/drivers/net/usb/usbnet.c +++ b/drivers/net/usb/usbnet.c @@ -1645,6 +1645,8 @@ 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); -- 2.51.0