This is a note to let you know that I have just added a patch titled
Subject: [PATCH 18/21] drm/i915: Sanity check pread/pwrite
to the drm-next branch of the 2.6.32+drm33-longterm tree which can be found at
http://git.kernel.org/?p=linux/kernel/git/smb/linux-2.6.32.y-drm33.z.git;a=shortlog;h=refs/heads/drm-next
If you, or anyone else, feels it should not be added to the drm33-longterm tree,
please reply to this email not later than 8 days after this email was sent.
Thanks.
-Stefan
------
>From 8cea8a6e94c1fb4a56c800752947340cca01221f Mon Sep 17 00:00:00 2001
From: Chris Wilson <[email protected]>
Date: Sun, 26 Sep 2010 20:50:05 +0100
Subject: [PATCH 18/21] drm/i915: Sanity check pread/pwrite
commit ce9d419dbecc292cc3e06e8b1d6d123d3fa813a4 upstream.
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 <[email protected]>
Signed-off-by: Chris Wilson <[email protected]>
Cc: [email protected]
[Backported to Debian's 2.6.32 by dann frazier <[email protected]>]
Signed-off-by: Ben Hutchings <[email protected]>
Signed-off-by: Stefan Bader <[email protected]>
---
drivers/gpu/drm/i915/i915_gem.c | 28 ++++++++++++++++++++--------
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 ad3c4a2..366abe3 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -488,8 +488,15 @@ 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(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)) {
@@ -501,8 +508,8 @@ i915_gem_pread_ioctl(struct drm_device *dev, void *data,
file_priv);
}
+err:
drm_gem_object_unreference(obj);
-
return ret;
}
@@ -592,8 +599,6 @@ 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);
@@ -961,8 +966,15 @@ 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(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
@@ -995,8 +1007,8 @@ i915_gem_pwrite_ioctl(struct drm_device *dev, void *data,
DRM_INFO("pwrite failed %d\n", ret);
#endif
+err:
drm_gem_object_unreference(obj);
-
return ret;
}
--
1.7.0.4