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=-12.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 4D7AFC5B578 for ; Mon, 1 Jul 2019 06:50:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1F3162145D for ; Mon, 1 Jul 2019 06:50:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1561963858; bh=RdXzx1UY54ct2gXZFCJPrEettps9v0qmG+73CbmC8QE=; h=Subject:To:From:Date:List-ID:From; b=2OWDmYcopfOhSc3hXB3+jvb/ERlTiAIx2ZS7Mpd37/Zq5/Ojfu10jUSRpxOQ5emym e9ZdAm3Byw3GoPVWCWjYmqvapqpDfbKFMw05QToXeVWBKG3s7bcbaM+lgvCqqt6Uys R2rM/2CdolcuTXRI8ERVbmjzuYOy9FWQek6/EjcA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727159AbfGAGu5 (ORCPT ); Mon, 1 Jul 2019 02:50:57 -0400 Received: from mail.kernel.org ([198.145.29.99]:42994 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725997AbfGAGu5 (ORCPT ); Mon, 1 Jul 2019 02:50:57 -0400 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 1FB042145D; Mon, 1 Jul 2019 06:50:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1561963856; bh=RdXzx1UY54ct2gXZFCJPrEettps9v0qmG+73CbmC8QE=; h=Subject:To:From:Date:From; b=d5IwyvCULWhB+0q49Ro1GOxUEPyOwEIQOdU+RxGUbWH7KzEUs6F18JZiX9zh3prkj 9y85GcRpky0nF1I+6BesoKxdmABCRZw+Mx/pj7kGBDn1f2GwbyzTdwADNT6TXD3v6n IZCHgIcfPAlQBWTfSv3MZo9AftXCwXovef5k5xSg= Subject: patch "staging: comedi: dt282x: fix a null pointer deref on interrupt" added to staging-testing To: abbotti@mev.co.uk, gregkh@linuxfoundation.org, stable@vger.kernel.org From: Date: Mon, 01 Jul 2019 08:50:41 +0200 Message-ID: <1561963841182249@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org This is a note to let you know that I've just added the patch titled staging: comedi: dt282x: fix a null pointer deref on interrupt to my staging git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging.git in the staging-testing branch. The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.) The patch will be merged to the staging-next branch sometime soon, after it passes testing, and the merge window is open. If you have any questions about this process, please let me know. >From b8336be66dec06bef518030a0df9847122053ec5 Mon Sep 17 00:00:00 2001 From: Ian Abbott Date: Wed, 26 Jun 2019 14:18:04 +0100 Subject: staging: comedi: dt282x: fix a null pointer deref on interrupt The interrupt handler `dt282x_interrupt()` causes a null pointer dereference for those supported boards that have no analog output support. For these boards, `dev->write_subdev` will be `NULL` and therefore the `s_ao` subdevice pointer variable will be `NULL`. In that case, the following call near the end of the interrupt handler results in a null pointer dereference: comedi_handle_events(dev, s_ao); Fix it by only calling the above function if `s_ao` is valid. (There are other uses of `s_ao` by the interrupt handler that may or may not be reached depending on values of hardware registers. Trust that they are reliable for now.) Note: commit 4f6f009b204f ("staging: comedi: dt282x: use comedi_handle_events()") propagates an earlier error from commit f21c74fa4cfe ("staging: comedi: dt282x: use cfc_handle_events()"). Fixes: 4f6f009b204f ("staging: comedi: dt282x: use comedi_handle_events()") Cc: # v3.19+ Signed-off-by: Ian Abbott Signed-off-by: Greg Kroah-Hartman --- drivers/staging/comedi/drivers/dt282x.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/staging/comedi/drivers/dt282x.c b/drivers/staging/comedi/drivers/dt282x.c index 3be927f1d3a9..e15e33ed94ae 100644 --- a/drivers/staging/comedi/drivers/dt282x.c +++ b/drivers/staging/comedi/drivers/dt282x.c @@ -557,7 +557,8 @@ static irqreturn_t dt282x_interrupt(int irq, void *d) } #endif comedi_handle_events(dev, s); - comedi_handle_events(dev, s_ao); + if (s_ao) + comedi_handle_events(dev, s_ao); return IRQ_RETVAL(handled); } -- 2.22.0