From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758075AbaISV3s (ORCPT ); Fri, 19 Sep 2014 17:29:48 -0400 Received: from ozlabs.org ([103.22.144.67]:43948 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757728AbaISV3p (ORCPT ); Fri, 19 Sep 2014 17:29:45 -0400 Date: Sat, 20 Sep 2014 07:29:42 +1000 From: Anton Blanchard To: Peter Huewe , Ashley Lai , Marcel Selhorst Cc: tpmdd-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org Subject: [PATCH 1/2] tpm/tpm_ibmvtpm: Fail in ibmvtpm_get_data if driver_data is bad Message-ID: <20140920072942.27c28768@kryten> X-Mailer: Claws Mail 3.9.3 (GTK+ 2.24.23; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org I'm looking at an oops in tpm_ibmvtpm_get_desired_dma: 28: 00 00 20 39 li r9,0 2c: 10 00 01 e8 ld r0,16(r1) 30: 28 00 69 80 lwz r3,40(r9) We set r9 to 0 then load r9+40. The problem is actually in ibmvtpm_get_data, it can return NULL but the rest of the driver never expects it. Add a BUG_ON in ibmvtpm_get_data. We still need to identify the root cause but at least this makes it obvious what went wrong. Cc: stable@vger.kernel.org Signed-off-by: Anton Blanchard --- diff --git a/drivers/char/tpm/tpm_ibmvtpm.c b/drivers/char/tpm/tpm_ibmvtpm.c index af74c57..0d1eeba 100644 --- a/drivers/char/tpm/tpm_ibmvtpm.c +++ b/drivers/char/tpm/tpm_ibmvtpm.c @@ -63,9 +63,9 @@ static int ibmvtpm_send_crq(struct vio_dev *vdev, u64 w1, u64 w2) static struct ibmvtpm_dev *ibmvtpm_get_data(const struct device *dev) { struct tpm_chip *chip = dev_get_drvdata(dev); - if (chip) - return (struct ibmvtpm_dev *)TPM_VPRIV(chip); - return NULL; + + BUG_ON(!chip); + return (struct ibmvtpm_dev *)TPM_VPRIV(chip); } /**