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authorChris Wilson <chris@chris-wilson.co.uk>2010-09-26 20:50:05 +0100
committerChris Wilson <chris@chris-wilson.co.uk>2010-10-03 14:16:17 +0100
commitce9d419dbecc292cc3e06e8b1d6d123d3fa813a4 (patch)
treea65b65d58e52bb05b3f08c6610f5d6345e5f4879
parentab7ad7f6451580aa7eccc0ba62807c872088a8f9 (diff)
downloadlinux-stericsson-ce9d419dbecc292cc3e06e8b1d6d123d3fa813a4.tar.gz
drm/i915: Sanity check pread/pwrite
Move the access control up from the fast paths, which are no longer universally taken first, up into the caller. This then duplicates some sanity checking along the slow paths, but is much simpler. Tracked as CVE-2010-2962. Reported-by: Kees Cook <kees@ubuntu.com> Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: stable@kernel.org
-rw-r--r--drivers/gpu/drm/i915/i915_gem.c28
1 files changed, 20 insertions, 8 deletions
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index cfe597865f5d..7749e78a7300 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -477,8 +477,15 @@ i915_gem_pread_ioctl(struct drm_device *dev, void *data,
*/
if (args->offset > obj->size || args->size > obj->size ||
args->offset + args->size > obj->size) {
- drm_gem_object_unreference_unlocked(obj);
- return -EINVAL;
+ ret = -EINVAL;
+ goto err;
+ }
+
+ if (!access_ok(VERIFY_WRITE,
+ (char __user *)(uintptr_t)args->data_ptr,
+ args->size)) {
+ ret = -EFAULT;
+ goto err;
}
if (i915_gem_object_needs_bit17_swizzle(obj)) {
@@ -490,8 +497,8 @@ i915_gem_pread_ioctl(struct drm_device *dev, void *data,
file_priv);
}
+err:
drm_gem_object_unreference_unlocked(obj);
-
return ret;
}
@@ -580,8 +587,6 @@ i915_gem_gtt_pwrite_fast(struct drm_device *dev, struct drm_gem_object *obj,
user_data = (char __user *) (uintptr_t) args->data_ptr;
remain = args->size;
- if (!access_ok(VERIFY_READ, user_data, remain))
- return -EFAULT;
mutex_lock(&dev->struct_mutex);
@@ -940,8 +945,15 @@ i915_gem_pwrite_ioctl(struct drm_device *dev, void *data,
*/
if (args->offset > obj->size || args->size > obj->size ||
args->offset + args->size > obj->size) {
- drm_gem_object_unreference_unlocked(obj);
- return -EINVAL;
+ ret = -EINVAL;
+ goto err;
+ }
+
+ if (!access_ok(VERIFY_READ,
+ (char __user *)(uintptr_t)args->data_ptr,
+ args->size)) {
+ ret = -EFAULT;
+ goto err;
}
/* We can only do the GTT pwrite on untiled buffers, as otherwise
@@ -975,8 +987,8 @@ i915_gem_pwrite_ioctl(struct drm_device *dev, void *data,
DRM_INFO("pwrite failed %d\n", ret);
#endif
+err:
drm_gem_object_unreference_unlocked(obj);
-
return ret;
}