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=-19.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=unavailable 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 73C87C433B4 for ; Fri, 30 Apr 2021 14:21:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 52E5361450 for ; Fri, 30 Apr 2021 14:21:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233483AbhD3OWQ (ORCPT ); Fri, 30 Apr 2021 10:22:16 -0400 Received: from mail.kernel.org ([198.145.29.99]:58446 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233278AbhD3OV7 (ORCPT ); Fri, 30 Apr 2021 10:21:59 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 20628613A9; Fri, 30 Apr 2021 14:21:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1619792471; bh=zpIW2u9iH5OdC5H6HFelvBfnbS5UkEcsuLSmrlKJ6oI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=yvKTLv3mk+oNpdxwL9sS00MV5l2mNV3dFNusAtTFio4HfxLqGf4ApPJ4AsUr92jho 9j4Rj59XF/AWo+27jQv6a83UO2kxgPVLy2ntxCcAtzKyCfQIF3XYhypV3uKiQ89ddS brONsUAYUXN/01aoUMbFSvFaAMRqF9s6o4rBaRBk= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Anirudh Rayabharam , Leonardo Antoniazzi , Johan Hovold , "David S. Miller" Subject: [PATCH 5.12 1/5] net: hso: fix NULL-deref on disconnect regression Date: Fri, 30 Apr 2021 16:20:56 +0200 Message-Id: <20210430141910.945061629@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210430141910.899518186@linuxfoundation.org> References: <20210430141910.899518186@linuxfoundation.org> User-Agent: quilt/0.66 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Johan Hovold commit 2ad5692db72874f02b9ad551d26345437ea4f7f3 upstream. Commit 8a12f8836145 ("net: hso: fix null-ptr-deref during tty device unregistration") fixed the racy minor allocation reported by syzbot, but introduced an unconditional NULL-pointer dereference on every disconnect instead. Specifically, the serial device table must no longer be accessed after the minor has been released by hso_serial_tty_unregister(). Fixes: 8a12f8836145 ("net: hso: fix null-ptr-deref during tty device unregistration") Cc: stable@vger.kernel.org Cc: Anirudh Rayabharam Reported-by: Leonardo Antoniazzi Signed-off-by: Johan Hovold Reviewed-by: Anirudh Rayabharam Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- drivers/net/usb/hso.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/net/usb/hso.c +++ b/drivers/net/usb/hso.c @@ -3104,7 +3104,7 @@ static void hso_free_interface(struct us cancel_work_sync(&serial_table[i]->async_put_intf); cancel_work_sync(&serial_table[i]->async_get_intf); hso_serial_tty_unregister(serial); - kref_put(&serial_table[i]->ref, hso_serial_ref_free); + kref_put(&serial->parent->ref, hso_serial_ref_free); } }