android_kernel_motorola_sm6225/drivers/gpu/drm/drm_ioctl.c
Vegard Nossum 1147c9cdd0 drm: fix leak of uninitialized data to userspace
...so drm_getunique() is trying to copy some uninitialized data to
userspace. The ECX register contains the number of words that are
left to copy -- so there are 5 * 4 = 20 bytes left. The offset of the
first uninitialized byte (counting from the start of the string) is
also 20 (i.e. 0xf65d2294&((1 << 5)-1) == 20). So somebody tried to
copy 40 bytes when the string was only 19 long.

In drm_set_busid() we have this code:

        dev->unique_len = 40;
        dev->unique = drm_alloc(dev->unique_len + 1, DRM_MEM_DRIVER);
      ...
        len = snprintf(dev->unique, dev->unique_len, pci:%04x:%02x:%02x.%d",

...so it seems that dev->unique is never updated to reflect the
actual length of the string. The remaining bytes (20 in this case)
are random uninitialized bytes that are copied into userspace.

This patch fixes the problem by setting dev->unique_len after the
snprintf().

airlied- I've had to fix this up to store the alloced size so
we have it for drm_free later.

Reported-by: Sitsofe Wheeler <sitsofe@yahoo.com>
Signed-off-by: Vegard Nossum <vegardno@thuin.ifi.uio.no>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2008-12-29 17:47:22 +10:00

359 lines
9.2 KiB
C

/**
* \file drm_ioctl.c
* IOCTL processing for DRM
*
* \author Rickard E. (Rik) Faith <faith@valinux.com>
* \author Gareth Hughes <gareth@valinux.com>
*/
/*
* Created: Fri Jan 8 09:01:26 1999 by faith@valinux.com
*
* Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
* Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
* All Rights Reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the next
* paragraph) shall be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*/
#include "drmP.h"
#include "drm_core.h"
#include "linux/pci.h"
/**
* Get the bus id.
*
* \param inode device inode.
* \param file_priv DRM file private.
* \param cmd command.
* \param arg user argument, pointing to a drm_unique structure.
* \return zero on success or a negative number on failure.
*
* Copies the bus id from drm_device::unique into user space.
*/
int drm_getunique(struct drm_device *dev, void *data,
struct drm_file *file_priv)
{
struct drm_unique *u = data;
struct drm_master *master = file_priv->master;
if (u->unique_len >= master->unique_len) {
if (copy_to_user(u->unique, master->unique, master->unique_len))
return -EFAULT;
}
u->unique_len = master->unique_len;
return 0;
}
/**
* Set the bus id.
*
* \param inode device inode.
* \param file_priv DRM file private.
* \param cmd command.
* \param arg user argument, pointing to a drm_unique structure.
* \return zero on success or a negative number on failure.
*
* Copies the bus id from userspace into drm_device::unique, and verifies that
* it matches the device this DRM is attached to (EINVAL otherwise). Deprecated
* in interface version 1.1 and will return EBUSY when setversion has requested
* version 1.1 or greater.
*/
int drm_setunique(struct drm_device *dev, void *data,
struct drm_file *file_priv)
{
struct drm_unique *u = data;
struct drm_master *master = file_priv->master;
int domain, bus, slot, func, ret;
if (master->unique_len || master->unique)
return -EBUSY;
if (!u->unique_len || u->unique_len > 1024)
return -EINVAL;
master->unique_len = u->unique_len;
master->unique_size = u->unique_len + 1;
master->unique = drm_alloc(master->unique_size, DRM_MEM_DRIVER);
if (!master->unique)
return -ENOMEM;
if (copy_from_user(master->unique, u->unique, master->unique_len))
return -EFAULT;
master->unique[master->unique_len] = '\0';
dev->devname =
drm_alloc(strlen(dev->driver->pci_driver.name) +
strlen(master->unique) + 2, DRM_MEM_DRIVER);
if (!dev->devname)
return -ENOMEM;
sprintf(dev->devname, "%s@%s", dev->driver->pci_driver.name,
master->unique);
/* Return error if the busid submitted doesn't match the device's actual
* busid.
*/
ret = sscanf(master->unique, "PCI:%d:%d:%d", &bus, &slot, &func);
if (ret != 3)
return -EINVAL;
domain = bus >> 8;
bus &= 0xff;
if ((domain != drm_get_pci_domain(dev)) ||
(bus != dev->pdev->bus->number) ||
(slot != PCI_SLOT(dev->pdev->devfn)) ||
(func != PCI_FUNC(dev->pdev->devfn)))
return -EINVAL;
return 0;
}
static int drm_set_busid(struct drm_device *dev, struct drm_file *file_priv)
{
struct drm_master *master = file_priv->master;
int len;
if (master->unique != NULL)
return -EBUSY;
master->unique_len = 40;
master->unique_size = master->unique_len;
master->unique = drm_alloc(master->unique_size, DRM_MEM_DRIVER);
if (master->unique == NULL)
return -ENOMEM;
len = snprintf(master->unique, master->unique_len, "pci:%04x:%02x:%02x.%d",
drm_get_pci_domain(dev),
dev->pdev->bus->number,
PCI_SLOT(dev->pdev->devfn),
PCI_FUNC(dev->pdev->devfn));
if (len >= master->unique_len)
DRM_ERROR("buffer overflow");
else
master->unique_len = len;
dev->devname =
drm_alloc(strlen(dev->driver->pci_driver.name) + master->unique_len +
2, DRM_MEM_DRIVER);
if (dev->devname == NULL)
return -ENOMEM;
sprintf(dev->devname, "%s@%s", dev->driver->pci_driver.name,
master->unique);
return 0;
}
/**
* Get a mapping information.
*
* \param inode device inode.
* \param file_priv DRM file private.
* \param cmd command.
* \param arg user argument, pointing to a drm_map structure.
*
* \return zero on success or a negative number on failure.
*
* Searches for the mapping with the specified offset and copies its information
* into userspace
*/
int drm_getmap(struct drm_device *dev, void *data,
struct drm_file *file_priv)
{
struct drm_map *map = data;
struct drm_map_list *r_list = NULL;
struct list_head *list;
int idx;
int i;
idx = map->offset;
mutex_lock(&dev->struct_mutex);
if (idx < 0) {
mutex_unlock(&dev->struct_mutex);
return -EINVAL;
}
i = 0;
list_for_each(list, &dev->maplist) {
if (i == idx) {
r_list = list_entry(list, struct drm_map_list, head);
break;
}
i++;
}
if (!r_list || !r_list->map) {
mutex_unlock(&dev->struct_mutex);
return -EINVAL;
}
map->offset = r_list->map->offset;
map->size = r_list->map->size;
map->type = r_list->map->type;
map->flags = r_list->map->flags;
map->handle = (void *)(unsigned long) r_list->user_token;
map->mtrr = r_list->map->mtrr;
mutex_unlock(&dev->struct_mutex);
return 0;
}
/**
* Get client information.
*
* \param inode device inode.
* \param file_priv DRM file private.
* \param cmd command.
* \param arg user argument, pointing to a drm_client structure.
*
* \return zero on success or a negative number on failure.
*
* Searches for the client with the specified index and copies its information
* into userspace
*/
int drm_getclient(struct drm_device *dev, void *data,
struct drm_file *file_priv)
{
struct drm_client *client = data;
struct drm_file *pt;
int idx;
int i;
idx = client->idx;
mutex_lock(&dev->struct_mutex);
i = 0;
list_for_each_entry(pt, &dev->filelist, lhead) {
if (i++ >= idx) {
client->auth = pt->authenticated;
client->pid = pt->pid;
client->uid = pt->uid;
client->magic = pt->magic;
client->iocs = pt->ioctl_count;
mutex_unlock(&dev->struct_mutex);
return 0;
}
}
mutex_unlock(&dev->struct_mutex);
return -EINVAL;
}
/**
* Get statistics information.
*
* \param inode device inode.
* \param file_priv DRM file private.
* \param cmd command.
* \param arg user argument, pointing to a drm_stats structure.
*
* \return zero on success or a negative number on failure.
*/
int drm_getstats(struct drm_device *dev, void *data,
struct drm_file *file_priv)
{
struct drm_stats *stats = data;
int i;
memset(stats, 0, sizeof(*stats));
mutex_lock(&dev->struct_mutex);
for (i = 0; i < dev->counters; i++) {
if (dev->types[i] == _DRM_STAT_LOCK)
stats->data[i].value =
(file_priv->master->lock.hw_lock ? file_priv->master->lock.hw_lock->lock : 0);
else
stats->data[i].value = atomic_read(&dev->counts[i]);
stats->data[i].type = dev->types[i];
}
stats->count = dev->counters;
mutex_unlock(&dev->struct_mutex);
return 0;
}
/**
* Setversion ioctl.
*
* \param inode device inode.
* \param file_priv DRM file private.
* \param cmd command.
* \param arg user argument, pointing to a drm_lock structure.
* \return zero on success or negative number on failure.
*
* Sets the requested interface version
*/
int drm_setversion(struct drm_device *dev, void *data, struct drm_file *file_priv)
{
struct drm_set_version *sv = data;
int if_version, retcode = 0;
if (sv->drm_di_major != -1) {
if (sv->drm_di_major != DRM_IF_MAJOR ||
sv->drm_di_minor < 0 || sv->drm_di_minor > DRM_IF_MINOR) {
retcode = -EINVAL;
goto done;
}
if_version = DRM_IF_VERSION(sv->drm_di_major,
sv->drm_di_minor);
dev->if_version = max(if_version, dev->if_version);
if (sv->drm_di_minor >= 1) {
/*
* Version 1.1 includes tying of DRM to specific device
*/
drm_set_busid(dev, file_priv);
}
}
if (sv->drm_dd_major != -1) {
if (sv->drm_dd_major != dev->driver->major ||
sv->drm_dd_minor < 0 || sv->drm_dd_minor >
dev->driver->minor) {
retcode = -EINVAL;
goto done;
}
if (dev->driver->set_version)
dev->driver->set_version(dev, sv);
}
done:
sv->drm_di_major = DRM_IF_MAJOR;
sv->drm_di_minor = DRM_IF_MINOR;
sv->drm_dd_major = dev->driver->major;
sv->drm_dd_minor = dev->driver->minor;
return retcode;
}
/** No-op ioctl. */
int drm_noop(struct drm_device *dev, void *data,
struct drm_file *file_priv)
{
DRM_DEBUG("\n");
return 0;
}