From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:60230 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751121AbdBXQax (ORCPT ); Fri, 24 Feb 2017 11:30:53 -0500 Subject: patch "staging: comedi: jr3_pci: fix possible null pointer dereference" added to staging-testing To: abbotti@mev.co.uk, gregkh@linuxfoundation.org, stable@vger.kernel.org From: Date: Fri, 24 Feb 2017 17:22:38 +0100 Message-ID: <1487953358238157@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 List-ID: This is a note to let you know that I've just added the patch titled staging: comedi: jr3_pci: fix possible null pointer dereference 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 631202ab1a6a59f13ae7268b11f76057ee9f0ca1 Mon Sep 17 00:00:00 2001 From: Ian Abbott Date: Fri, 17 Feb 2017 11:09:08 +0000 Subject: staging: comedi: jr3_pci: fix possible null pointer dereference For some reason, the driver does not consider allocation of the subdevice private data to be a fatal error when attaching the COMEDI device. It tests the subdevice private data pointer for validity at certain points, but omits some crucial tests. In particular, `jr3_pci_auto_attach()` calls `jr3_pci_alloc_spriv()` to allocate and initialize the subdevice private data, but the same function subsequently dereferences the pointer to access the `next_time_min` and `next_time_max` members without checking it first. The other missing test is in the timer expiry routine `jr3_pci_poll_dev()`, but it will crash before it gets that far. Fix the bug by returning `-ENOMEM` from `jr3_pci_auto_attach()` as soon as one of the calls to `jr3_pci_alloc_spriv()` returns `NULL`. The COMEDI core will subsequently call `jr3_pci_detach()` to clean up. Cc: # 3.15+ Signed-off-by: Ian Abbott Signed-off-by: Greg Kroah-Hartman --- drivers/staging/comedi/drivers/jr3_pci.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/drivers/staging/comedi/drivers/jr3_pci.c b/drivers/staging/comedi/drivers/jr3_pci.c index 70390de66e0e..25909a936e7c 100644 --- a/drivers/staging/comedi/drivers/jr3_pci.c +++ b/drivers/staging/comedi/drivers/jr3_pci.c @@ -727,11 +727,12 @@ static int jr3_pci_auto_attach(struct comedi_device *dev, s->insn_read = jr3_pci_ai_insn_read; spriv = jr3_pci_alloc_spriv(dev, s); - if (spriv) { - /* Channel specific range and maxdata */ - s->range_table_list = spriv->range_table_list; - s->maxdata_list = spriv->maxdata_list; - } + if (!spriv) + return -ENOMEM; + + /* Channel specific range and maxdata */ + s->range_table_list = spriv->range_table_list; + s->maxdata_list = spriv->maxdata_list; } /* Reset DSP card */ -- 2.11.1