From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jon Mason Subject: [PATCH 3.11 91/94] NTB: Add Error Handling in ntb_device_setup Date: Fri, 8 Nov 2013 22:52:37 -0800 Message-Id: <20131109065210.674026089@linuxfoundation.org> In-Reply-To: <20131109065204.252462489@linuxfoundation.org> References: <20131109065204.252462489@linuxfoundation.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.11-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jon Mason commit 3b12a0d15bd1559e72ad21d9d807fd2a6706f0ab upstream. If an error is encountered in ntb_device_setup, it is possible that the spci_cmd isn't populated. Writes to the offset can result in a NULL pointer dereference. This issue is easily encountered by running in NTB-RP mode, as it currently is not supported and will generate an error. To get around this issue, return if an error is encountered prior to attempting to write to the spci_cmd offset. Signed-off-by: Jon Mason Signed-off-by: Greg Kroah-Hartman --- drivers/ntb/ntb_hw.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) --- a/drivers/ntb/ntb_hw.c +++ b/drivers/ntb/ntb_hw.c @@ -644,10 +644,13 @@ static int ntb_device_setup(struct ntb_d rc = -ENODEV; } + if (rc) + return rc; + /* Enable Bus Master and Memory Space on the secondary side */ writew(PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER, ndev->reg_ofs.spci_cmd); - return rc; + return 0; } static void ntb_device_free(struct ntb_device *ndev)