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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E85B8C4332F for ; Mon, 25 Oct 2021 19:36:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CB74761181 for ; Mon, 25 Oct 2021 19:36:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236332AbhJYTiL (ORCPT ); Mon, 25 Oct 2021 15:38:11 -0400 Received: from mail.kernel.org ([198.145.29.99]:48432 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235143AbhJYTbl (ORCPT ); Mon, 25 Oct 2021 15:31:41 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 16FB961152; Mon, 25 Oct 2021 19:27:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1635190069; bh=l6yUpv24CZ2qGfC2ClqOhdk8gfzcGesEs6/bflsTob0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=z0C2qipQxTSZrS+Bgd3uiSEsSUPndlwjtP+Q9R6ZAJjPcuKlx19WuVqLhieD394Vh doxz8QGBTjnhX+DWpe1hZyIqNWejj0v/BfH+k40oleQODVuAAbbhHN4S00hs7jW+2q xgjlTgKxgJzZ672g+D7ZWCT2oO9UNHrPF357Ur/Y= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Xiaolong Huang , Arnd Bergmann , Jakub Kicinski Subject: [PATCH 5.4 42/58] isdn: cpai: check ctr->cnr to avoid array index out of bound Date: Mon, 25 Oct 2021 21:14:59 +0200 Message-Id: <20211025190944.286762303@linuxfoundation.org> X-Mailer: git-send-email 2.33.1 In-Reply-To: <20211025190937.555108060@linuxfoundation.org> References: <20211025190937.555108060@linuxfoundation.org> User-Agent: quilt/0.66 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: Xiaolong Huang commit 1f3e2e97c003f80c4b087092b225c8787ff91e4d upstream. The cmtp_add_connection() would add a cmtp session to a controller and run a kernel thread to process cmtp. __module_get(THIS_MODULE); session->task = kthread_run(cmtp_session, session, "kcmtpd_ctr_%d", session->num); During this process, the kernel thread would call detach_capi_ctr() to detach a register controller. if the controller was not attached yet, detach_capi_ctr() would trigger an array-index-out-bounds bug. [ 46.866069][ T6479] UBSAN: array-index-out-of-bounds in drivers/isdn/capi/kcapi.c:483:21 [ 46.867196][ T6479] index -1 is out of range for type 'capi_ctr *[32]' [ 46.867982][ T6479] CPU: 1 PID: 6479 Comm: kcmtpd_ctr_0 Not tainted 5.15.0-rc2+ #8 [ 46.869002][ T6479] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-2 04/01/2014 [ 46.870107][ T6479] Call Trace: [ 46.870473][ T6479] dump_stack_lvl+0x57/0x7d [ 46.870974][ T6479] ubsan_epilogue+0x5/0x40 [ 46.871458][ T6479] __ubsan_handle_out_of_bounds.cold+0x43/0x48 [ 46.872135][ T6479] detach_capi_ctr+0x64/0xc0 [ 46.872639][ T6479] cmtp_session+0x5c8/0x5d0 [ 46.873131][ T6479] ? __init_waitqueue_head+0x60/0x60 [ 46.873712][ T6479] ? cmtp_add_msgpart+0x120/0x120 [ 46.874256][ T6479] kthread+0x147/0x170 [ 46.874709][ T6479] ? set_kthread_struct+0x40/0x40 [ 46.875248][ T6479] ret_from_fork+0x1f/0x30 [ 46.875773][ T6479] Signed-off-by: Xiaolong Huang Acked-by: Arnd Bergmann Link: https://lore.kernel.org/r/20211008065830.305057-1-butterflyhuangxx@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman --- drivers/isdn/capi/kcapi.c | 5 +++++ 1 file changed, 5 insertions(+) --- a/drivers/isdn/capi/kcapi.c +++ b/drivers/isdn/capi/kcapi.c @@ -565,6 +565,11 @@ int detach_capi_ctr(struct capi_ctr *ctr ctr_down(ctr, CAPI_CTR_DETACHED); + if (ctr->cnr < 1 || ctr->cnr - 1 >= CAPI_MAXCONTR) { + err = -EINVAL; + goto unlock_out; + } + if (capi_controller[ctr->cnr - 1] != ctr) { err = -EINVAL; goto unlock_out;