From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4B352C2D0BF for ; Mon, 16 Dec 2019 17:56:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 244CE20733 for ; Mon, 16 Dec 2019 17:56:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1576518965; bh=ZR19IDXpPk3hAdCKhmbkx3xf7pwKHMAIoGz17JSoSRQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=XHvN6D0e2kOUcYc4dkXciZddv2uLW++toHAIoVuiwlmfDe3yU9QyWpB/P1nFfLUg4 x5hbnRXf43kbqk2GeSnMtWzP6JAwVcGVowfih+AhbsErkpc6y9HjSKe/NwrFHWcMk5 pZj0xT24r3VKtDo3ntOBhZBcyG25rA9+5YPZYrrg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728151AbfLPR4E (ORCPT ); Mon, 16 Dec 2019 12:56:04 -0500 Received: from mail.kernel.org ([198.145.29.99]:53686 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728132AbfLPR4A (ORCPT ); Mon, 16 Dec 2019 12:56:00 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id BECCB205ED; Mon, 16 Dec 2019 17:55:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1576518959; bh=ZR19IDXpPk3hAdCKhmbkx3xf7pwKHMAIoGz17JSoSRQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=YoH94wNBDeEq2FjyVDw0+jTDMp7/nB8D43WmZ07KjfHTqgilqFK89DKK08PLtA64p 1qwbzvU6EKq4G3M0KA1/U7cNwfq0mzo2qWyKUPvKc4jM8qaq9tQRYcXyH6J/zK17mb hHGqwZMRhYwz9nfFGRYCSgy65Djo3MH7Okhn4n5Y= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Wolfgang Grandegger , Marc Kleine-Budde , David Miller , Oliver Hartkopp , Lukas Bulwahn , Jouni Hogander Subject: [PATCH 4.14 136/267] can: slcan: Fix use-after-free Read in slcan_open Date: Mon, 16 Dec 2019 18:47:42 +0100 Message-Id: <20191216174908.362665521@linuxfoundation.org> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20191216174848.701533383@linuxfoundation.org> References: <20191216174848.701533383@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jouni Hogander commit 9ebd796e24008f33f06ebea5a5e6aceb68b51794 upstream. Slcan_open doesn't clean-up device which registration failed from the slcan_devs device list. On next open this list is iterated and freed device is accessed. Fix this by calling slc_free_netdev in error path. Driver/net/can/slcan.c is derived from slip.c. Use-after-free error was identified in slip_open by syzboz. Same bug is in slcan.c. Here is the trace from the Syzbot slip report: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x197/0x210 lib/dump_stack.c:118 print_address_description.constprop.0.cold+0xd4/0x30b mm/kasan/report.c:374 __kasan_report.cold+0x1b/0x41 mm/kasan/report.c:506 kasan_report+0x12/0x20 mm/kasan/common.c:634 __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:132 sl_sync drivers/net/slip/slip.c:725 [inline] slip_open+0xecd/0x11b7 drivers/net/slip/slip.c:801 tty_ldisc_open.isra.0+0xa3/0x110 drivers/tty/tty_ldisc.c:469 tty_set_ldisc+0x30e/0x6b0 drivers/tty/tty_ldisc.c:596 tiocsetd drivers/tty/tty_io.c:2334 [inline] tty_ioctl+0xe8d/0x14f0 drivers/tty/tty_io.c:2594 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:509 [inline] do_vfs_ioctl+0xdb6/0x13e0 fs/ioctl.c:696 ksys_ioctl+0xab/0xd0 fs/ioctl.c:713 __do_sys_ioctl fs/ioctl.c:720 [inline] __se_sys_ioctl fs/ioctl.c:718 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718 do_syscall_64+0xfa/0x760 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Fixes: ed50e1600b44 ("slcan: Fix memory leak in error path") Cc: Wolfgang Grandegger Cc: Marc Kleine-Budde Cc: David Miller Cc: Oliver Hartkopp Cc: Lukas Bulwahn Signed-off-by: Jouni Hogander Cc: linux-stable # >= v5.4 Acked-by: Oliver Hartkopp Signed-off-by: Marc Kleine-Budde Signed-off-by: Greg Kroah-Hartman --- drivers/net/can/slcan.c | 1 + 1 file changed, 1 insertion(+) --- a/drivers/net/can/slcan.c +++ b/drivers/net/can/slcan.c @@ -613,6 +613,7 @@ err_free_chan: sl->tty = NULL; tty->disc_data = NULL; clear_bit(SLF_INUSE, &sl->flags); + slc_free_netdev(sl->dev); free_netdev(sl->dev); err_exit: