From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754584AbdBOXR4 (ORCPT ); Wed, 15 Feb 2017 18:17:56 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:53697 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752818AbdBOXRx (ORCPT ); Wed, 15 Feb 2017 18:17:53 -0500 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Greg Kroah-Hartman" , "Andy Shevchenko" , "Ladislav Michl" Date: Wed, 15 Feb 2017 22:41:40 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 076/306] Revert "usbtmc: convert to devm_kzalloc" In-Reply-To: X-SA-Exim-Connect-IP: 2a02:8011:400e:2:6f00:88c8:c921:d332 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.40-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Greg Kroah-Hartman commit ab21b63e8aedfc73565dd9cdd51eb338341177cb upstream. This reverts commit e6c7efdcb76f11b04e3d3f71c8d764ab75c9423b. Turns out it was totally wrong. The memory is supposed to be bound to the kref, as the original code was doing correctly, not the device/driver binding as the devm_kzalloc() would cause. This fixes an oops when read would be called after the device was unbound from the driver. Reported-by: Ladislav Michl Cc: Andy Shevchenko Signed-off-by: Greg Kroah-Hartman [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings --- drivers/usb/class/usbtmc.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/drivers/usb/class/usbtmc.c +++ b/drivers/usb/class/usbtmc.c @@ -120,6 +120,7 @@ static void usbtmc_delete(struct kref *k struct usbtmc_device_data *data = to_usbtmc_data(kref); usb_put_dev(data->usb_dev); + kfree(data); } static int usbtmc_open(struct inode *inode, struct file *filp) @@ -1103,7 +1104,7 @@ static int usbtmc_probe(struct usb_inter dev_dbg(&intf->dev, "%s called\n", __func__); - data = devm_kzalloc(&intf->dev, sizeof(*data), GFP_KERNEL); + data = kmalloc(sizeof(*data), GFP_KERNEL); if (!data) { dev_err(&intf->dev, "Unable to allocate kernel memory\n"); return -ENOMEM;