iommu: Fix wrong freeing of iommu_device->dev

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: 39ab9555c241 ('iommu: Add sysfs bindings for struct iommu_device')
Cc: stable@vger.kernel.org # >= v4.11
Signed-off-by: Joerg Roedel <jroedel@suse.de>

diff --git a/drivers/iommu/amd_iommu_types.h b/drivers/iommu/amd_iommu_types.h
index 294a409e283b7ae4b52c59350756983711bba9d1..d6b873b57054b44d2f0227630798cda83a637256 100644 (file)
--- a/drivers/iommu/amd_iommu_types.h
+++ b/drivers/iommu/amd_iommu_types.h
@@ -574,7 +574,9 @@ struct amd_iommu {
 
 static inline struct amd_iommu *dev_to_amd_iommu(struct device *dev)
 {
-       return container_of(dev, struct amd_iommu, iommu.dev);
+       struct iommu_device *iommu = dev_to_iommu_device(dev);
+
+       return container_of(iommu, struct amd_iommu, iommu);
 }
 
 #define ACPIHID_UID_LEN 256

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 687f18f65cea58d2a5f22725a2c36c78621dd3cd..3e8636f1220ea9bdbcf668bac193e21cee408063 100644 (file)
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -4736,7 +4736,9 @@ static void intel_disable_iommus(void)
 
 static inline struct intel_iommu *dev_to_intel_iommu(struct device *dev)
 {
-       return container_of(dev, struct intel_iommu, iommu.dev);
+       struct iommu_device *iommu_dev = dev_to_iommu_device(dev);
+
+       return container_of(iommu_dev, struct intel_iommu, iommu);
 }
 
 static ssize_t intel_iommu_show_version(struct device *dev,

diff --git a/drivers/iommu/iommu-sysfs.c b/drivers/iommu/iommu-sysfs.c
index c58351ed61c14309c7a72346bd56f659a7039637..36d1a7ce7fc4cc922cade9642b5d64c05e5d8e19 100644 (file)
--- a/drivers/iommu/iommu-sysfs.c
+++ b/drivers/iommu/iommu-sysfs.c
@@ -62,32 +62,40 @@ int iommu_device_sysfs_add(struct iommu_device *iommu,
        va_list vargs;
        int ret;
 
-       device_initialize(&iommu->dev);
+       iommu->dev = kzalloc(sizeof(*iommu->dev), GFP_KERNEL);
+       if (!iommu->dev)
+               return -ENOMEM;
 
-       iommu->dev.class = &iommu_class;
-       iommu->dev.parent = parent;
-       iommu->dev.groups = groups;
+       device_initialize(iommu->dev);
+
+       iommu->dev->class = &iommu_class;
+       iommu->dev->parent = parent;
+       iommu->dev->groups = groups;
 
        va_start(vargs, fmt);
-       ret = kobject_set_name_vargs(&iommu->dev.kobj, fmt, vargs);
+       ret = kobject_set_name_vargs(&iommu->dev->kobj, fmt, vargs);
        va_end(vargs);
        if (ret)
                goto error;
 
-       ret = device_add(&iommu->dev);
+       ret = device_add(iommu->dev);
        if (ret)
                goto error;
 
+       dev_set_drvdata(iommu->dev, iommu);
+
        return 0;
 
 error:
-       put_device(&iommu->dev);
+       put_device(iommu->dev);
        return ret;
 }
 
 void iommu_device_sysfs_remove(struct iommu_device *iommu)
 {
-       device_unregister(&iommu->dev);
+       dev_set_drvdata(iommu->dev, NULL);
+       device_unregister(iommu->dev);
+       iommu->dev = NULL;
 }
 /*
  * IOMMU drivers can indicate a device is managed by a given IOMMU using
@@ -102,14 +110,14 @@ int iommu_device_link(struct iommu_device *iommu, struct device *link)
        if (!iommu || IS_ERR(iommu))
                return -ENODEV;
 
-       ret = sysfs_add_link_to_group(&iommu->dev.kobj, "devices",
+       ret = sysfs_add_link_to_group(&iommu->dev->kobj, "devices",
                                      &link->kobj, dev_name(link));
        if (ret)
                return ret;
 
-       ret = sysfs_create_link_nowarn(&link->kobj, &iommu->dev.kobj, "iommu");
+       ret = sysfs_create_link_nowarn(&link->kobj, &iommu->dev->kobj, "iommu");
        if (ret)
-               sysfs_remove_link_from_group(&iommu->dev.kobj, "devices",
+               sysfs_remove_link_from_group(&iommu->dev->kobj, "devices",
                                             dev_name(link));
 
        return ret;
@@ -121,5 +129,5 @@ void iommu_device_unlink(struct iommu_device *iommu, struct device *link)
                return;
 
        sysfs_remove_link(&link->kobj, "iommu");
-       sysfs_remove_link_from_group(&iommu->dev.kobj, "devices", dev_name(link));
+       sysfs_remove_link_from_group(&iommu->dev->kobj, "devices", dev_name(link));
 }

diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 2cb54adc4a334aa3f3a1732c35eaf9749d64b9e8..176f7569d87408c1e57bf09846809bfef5b0b7c8 100644 (file)
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -240,7 +240,7 @@ struct iommu_device {
        struct list_head list;
        const struct iommu_ops *ops;
        struct fwnode_handle *fwnode;
-       struct device dev;
+       struct device *dev;
 };
 
 int  iommu_device_register(struct iommu_device *iommu);
@@ -265,6 +265,11 @@ static inline void iommu_device_set_fwnode(struct iommu_device *iommu,
        iommu->fwnode = fwnode;
 }
 
+static inline struct iommu_device *dev_to_iommu_device(struct device *dev)
+{
+       return (struct iommu_device *)dev_get_drvdata(dev);
+}
+
 #define IOMMU_GROUP_NOTIFY_ADD_DEVICE          1 /* Device added */
 #define IOMMU_GROUP_NOTIFY_DEL_DEVICE          2 /* Pre Device removed */
 #define IOMMU_GROUP_NOTIFY_BIND_DRIVER         3 /* Pre Driver bind */
@@ -589,6 +594,11 @@ static inline void iommu_device_set_fwnode(struct iommu_device *iommu,
 {
 }
 
+static inline struct iommu_device *dev_to_iommu_device(struct device *dev)
+{
+       return NULL;
+}
+
 static inline void iommu_device_unregister(struct iommu_device *iommu)
 {
 }