Commit 69ef943d authored by Matthew Wilcox's avatar Matthew Wilcox Committed by Dave Airlie

drm: Use array_size() when creating lease

Passing an object_count of sufficient size will make
object_count * 4 wrap around to be very small, then a later function
will happily iterate off the end of the object_ids array.  Using
array_size() will saturate at SIZE_MAX, the kmalloc() will fail and
we'll return an -ENOMEM to the norty userspace.

Fixes: 62884cd3 ("drm: Add four ioctls for managing drm mode object leases [v7]")
Signed-off-by: default avatarMatthew Wilcox <willy@infradead.org>
Acked-by: default avatarKees Cook <keescook@chromium.org>
Acked-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
Cc: <stable@vger.kernel.org> # v4.15+
Signed-off-by: default avatarDave Airlie <airlied@redhat.com>
parent 7abbb35b
...@@ -528,7 +528,8 @@ int drm_mode_create_lease_ioctl(struct drm_device *dev, ...@@ -528,7 +528,8 @@ int drm_mode_create_lease_ioctl(struct drm_device *dev,
object_count = cl->object_count; object_count = cl->object_count;
object_ids = memdup_user(u64_to_user_ptr(cl->object_ids), object_count * sizeof(__u32)); object_ids = memdup_user(u64_to_user_ptr(cl->object_ids),
array_size(object_count, sizeof(__u32)));
if (IS_ERR(object_ids)) if (IS_ERR(object_ids))
return PTR_ERR(object_ids); return PTR_ERR(object_ids);
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment