From 2926a2aa5c14fb2add75e6584845b1c03022235f Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Mon, 14 Aug 2017 17:19:26 +0200 Subject: [PATCH] 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 Fixes: 39ab9555c241 ('iommu: Add sysfs bindings for struct iommu_device') Cc: stable@vger.kernel.org # >= v4.11 Signed-off-by: Joerg Roedel --- drivers/iommu/amd_iommu_types.h | 4 +++- drivers/iommu/intel-iommu.c | 4 +++- drivers/iommu/iommu-sysfs.c | 32 ++++++++++++++++++++------------ include/linux/iommu.h | 12 +++++++++++- 4 files changed, 37 insertions(+), 15 deletions(-) diff --git a/drivers/iommu/amd_iommu_types.h b/drivers/iommu/amd_iommu_types.h index 294a409e283b..d6b873b57054 100644 --- 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 687f18f65cea..3e8636f1220e 100644 --- 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 c58351ed61c1..36d1a7ce7fc4 100644 --- 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 2cb54adc4a33..176f7569d874 100644 --- 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) { } -- 2.20.1