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 817521D6DB5; Tue, 11 Nov 2025 00:53:08 +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=1762822389; cv=none; b=MyAcxiPAu7TLRTpJkCPeP5DX6seTpYK9Ckyu8YvEF2zQHjsJ1D5XBLIDYqEvwg5NNsel8PgSeATgL3PAAqwv9wk5WeVzCAx9s97oPjpoC3aXbuiqctRhzS6keVhOhLPob55dDNQbkcnsHTP+FaLpdgLWvSZoDgy//hZAC8wKBFc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762822389; c=relaxed/simple; bh=qoOx7b0N0TgEvo0SlmeygX3Y+0GtwvUUewmDRBZZV4s=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=mBSC6iGPdgU/eKdaSsHVnOigzABdqMypVZKK5pZd/NmUvpPskVCX0uKH4uDp3Z/BRRD9hziJKxr+AOu9UbMFVTnlhWiQCsen5G7joWCuOHqWCLLdIDBP+0jGCzDtPjkivTLQ8bSnzVrXISdaTsExo91gDEys3k+CE9fIvLwL18A= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Ekoe6XII; 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="Ekoe6XII" Received: by smtp.kernel.org (Postfix) with ESMTPSA id AC0D8C4CEFB; Tue, 11 Nov 2025 00:53:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1762822388; bh=qoOx7b0N0TgEvo0SlmeygX3Y+0GtwvUUewmDRBZZV4s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Ekoe6XIIaeqjFkxYgjF4YxkKd9mvH0CBQVjcUOL6gewK01DuAJ4Ams1Fsa5iRmtVw zeN13Zd+z9qgVKJEmnuG16nZqQIz4JYjoaxHFHwv9mv77kLbQf4/U6i9zDv6o5OpHo YOb+AZZzpVs6bKIEp/kpfrfSFDL/DIx9M43fVy8E= 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 6.12 040/565] usbnet: Prevents free active kevent Date: Tue, 11 Nov 2025 09:38:16 +0900 Message-ID: <20251111004527.798972034@linuxfoundation.org> X-Mailer: git-send-email 2.51.2 In-Reply-To: <20251111004526.816196597@linuxfoundation.org> References: <20251111004526.816196597@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 6.12-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 ccf45ca2feb56..0ff7357c3c91c 100644 --- a/drivers/net/usb/usbnet.c +++ b/drivers/net/usb/usbnet.c @@ -1650,6 +1650,8 @@ 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