[Intel-gfx] [PATCH 4/5] drm/i915: Reject attempted pwrites into a read-only object

[Chris Wilson]

If the user created a read-only object, they should not be allowed to
circumvent the write protection using the pwrite ioctl.

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Jon Bloomfield <jon.bloomfield at intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
Cc: Matthew Auld <matthew.william.auld at gmail.com>
Reviewed-by: Jon Bloomfield <jon.bloomfield at intel.com>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
Reviewed-by: Matthew Auld <matthew.william.auld at gmail.com>
---
 drivers/gpu/drm/i915/i915_gem.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 2bfb16e83af2..47afe13638da 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -1623,6 +1623,12 @@ i915_gem_pwrite_ioctl(struct drm_device *dev, void *data,
 		goto err;
 	}
 
+	/* Writes not allowed into this read-only object */
+	if (i915_gem_object_is_readonly(obj)) {
+		ret = -EINVAL;
+		goto err;
+	}
+
 	trace_i915_gem_object_pwrite(obj, args->offset, args->size);
 
 	ret = -ENODEV;
-- 
2.17.1