From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pb0-f41.google.com ([209.85.160.41]:40214 "EHLO mail-pb0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751693Ab3FFRMd (ORCPT ); Thu, 6 Jun 2013 13:12:33 -0400 Received: by mail-pb0-f41.google.com with SMTP id rp16so1310pbb.0 for ; Thu, 06 Jun 2013 10:12:33 -0700 (PDT) From: Jiang Liu To: Bjorn Helgaas Cc: Jiang Liu , Yijing Wang , linux-pci@vger.kernel.org Subject: [PATCH 1/2] PCI: fix a double free issue in pci_create_root_bus() error recovery path Date: Fri, 7 Jun 2013 01:10:08 +0800 Message-Id: <1370538609-28903-1-git-send-email-jiang.liu@huawei.com> In-Reply-To: References: Sender: linux-pci-owner@vger.kernel.org List-ID: On pci_create_root_bus() error recovery path, device_unregister(&bridge->dev) should have freed memory used by bridge, so we shouldn't call kfree(bridge) again, it's a double free. On the other hand, we should not use kfree() to free memory used by device object once we have invoked device_register() because it's reference-counted. Signed-off-by: Jiang Liu Cc: stable@vger.kernel.org --- Hi Bjorn, This is the patch to fix the kfree() issue, it may be a material for stable trees. Thanks! Gerry --- drivers/pci/probe.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 8882b5d..2f81a0a 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -1729,12 +1729,16 @@ struct pci_bus *pci_create_root_bus(struct device *parent, int bus, bridge->dev.release = pci_release_bus_bridge_dev; dev_set_name(&bridge->dev, "pci%04x:%02x", pci_domain_nr(b), bus); error = pcibios_root_bridge_prepare(bridge); - if (error) - goto bridge_dev_reg_err; + if (error) { + kfree(bridge); + goto err_out; + } error = device_register(&bridge->dev); - if (error) - goto bridge_dev_reg_err; + if (error) { + kfree(bridge); + goto err_out; + } b->bridge = get_device(&bridge->dev); device_enable_async_suspend(b->bridge); pci_set_bus_of_node(b); @@ -1790,8 +1794,6 @@ struct pci_bus *pci_create_root_bus(struct device *parent, int bus, class_dev_reg_err: put_device(&bridge->dev); device_unregister(&bridge->dev); -bridge_dev_reg_err: - kfree(bridge); err_out: kfree(b); return NULL; -- 1.8.1.2