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2926a2aa5c
The struct iommu_device has a 'struct device' embedded into
it, not as a pointer, but the whole struct. In the
conversion of the iommu drivers to use struct iommu_device
it was forgotten that the relase function for that struct
device simply calls kfree() on the pointer.
This frees memory that was never allocated and causes memory
corruption.
To fix this issue, use a pointer to struct device instead of
embedding the whole struct. This needs some updates in the
iommu sysfs code as well as the Intel VT-d and AMD IOMMU
driver.
Reported-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Fixes: 39ab9555c2 ('iommu: Add sysfs bindings for struct iommu_device')
Cc: stable@vger.kernel.org # >= v4.11
Signed-off-by: Joerg Roedel <jroedel@suse.de>
134 lines
3.1 KiB
C
134 lines
3.1 KiB
C
/*
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* IOMMU sysfs class support
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*
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* Copyright (C) 2014 Red Hat, Inc. All rights reserved.
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* Author: Alex Williamson <alex.williamson@redhat.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/device.h>
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#include <linux/iommu.h>
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#include <linux/module.h>
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#include <linux/slab.h>
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/*
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* We provide a common class "devices" group which initially has no attributes.
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* As devices are added to the IOMMU, we'll add links to the group.
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*/
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static struct attribute *devices_attr[] = {
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NULL,
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};
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static const struct attribute_group iommu_devices_attr_group = {
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.name = "devices",
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.attrs = devices_attr,
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};
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static const struct attribute_group *iommu_dev_groups[] = {
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&iommu_devices_attr_group,
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NULL,
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};
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static void iommu_release_device(struct device *dev)
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{
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kfree(dev);
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}
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static struct class iommu_class = {
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.name = "iommu",
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.dev_release = iommu_release_device,
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.dev_groups = iommu_dev_groups,
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};
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static int __init iommu_dev_init(void)
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{
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return class_register(&iommu_class);
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}
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postcore_initcall(iommu_dev_init);
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/*
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* Init the struct device for the IOMMU. IOMMU specific attributes can
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* be provided as an attribute group, allowing a unique namespace per
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* IOMMU type.
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*/
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int iommu_device_sysfs_add(struct iommu_device *iommu,
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struct device *parent,
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const struct attribute_group **groups,
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const char *fmt, ...)
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{
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va_list vargs;
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int ret;
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iommu->dev = kzalloc(sizeof(*iommu->dev), GFP_KERNEL);
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if (!iommu->dev)
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return -ENOMEM;
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device_initialize(iommu->dev);
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iommu->dev->class = &iommu_class;
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iommu->dev->parent = parent;
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iommu->dev->groups = groups;
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va_start(vargs, fmt);
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ret = kobject_set_name_vargs(&iommu->dev->kobj, fmt, vargs);
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va_end(vargs);
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if (ret)
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goto error;
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ret = device_add(iommu->dev);
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if (ret)
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goto error;
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dev_set_drvdata(iommu->dev, iommu);
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return 0;
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error:
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put_device(iommu->dev);
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return ret;
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}
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void iommu_device_sysfs_remove(struct iommu_device *iommu)
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{
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dev_set_drvdata(iommu->dev, NULL);
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device_unregister(iommu->dev);
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iommu->dev = NULL;
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}
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/*
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* IOMMU drivers can indicate a device is managed by a given IOMMU using
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* this interface. A link to the device will be created in the "devices"
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* directory of the IOMMU device in sysfs and an "iommu" link will be
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* created under the linked device, pointing back at the IOMMU device.
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*/
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int iommu_device_link(struct iommu_device *iommu, struct device *link)
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{
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int ret;
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if (!iommu || IS_ERR(iommu))
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return -ENODEV;
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ret = sysfs_add_link_to_group(&iommu->dev->kobj, "devices",
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&link->kobj, dev_name(link));
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if (ret)
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return ret;
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ret = sysfs_create_link_nowarn(&link->kobj, &iommu->dev->kobj, "iommu");
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if (ret)
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sysfs_remove_link_from_group(&iommu->dev->kobj, "devices",
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dev_name(link));
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return ret;
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}
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void iommu_device_unlink(struct iommu_device *iommu, struct device *link)
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{
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if (!iommu || IS_ERR(iommu))
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return;
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sysfs_remove_link(&link->kobj, "iommu");
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sysfs_remove_link_from_group(&iommu->dev->kobj, "devices", dev_name(link));
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}
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