Re: [PATCH v2 2/3] drm/virtio: honor blob_alignment requirements
From: Alyssa Ross <hidden>
Date: 2026-07-01 11:10:35
Also in:
dri-devel, lkml
On Tue, Apr 28, 2026 at 09:44:49PM +0200, Sergio Lopez wrote:
If VIRTIO_GPU_F_BLOB_ALIGNMENT has been negotiated, blob size must be aligned to blob_alignment. Validate this in verify_blob() so that invalid requests are rejected early. Signed-off-by: Sergio Lopez <redacted>
FYI: this change breaks crosvm, which is squatting the 5 and 6 values of VIRTIO_GPU_F_* with different meanings. I've reported it as a crosvm bug, so hopefully it can be taken care of there. https://issuetracker.google.com/issues/529852979
quoted hunk ↗ jump to hunk
--- drivers/gpu/drm/virtio/virtgpu_ioctl.c | 5 +++++ 1 file changed, 5 insertions(+)diff --git a/drivers/gpu/drm/virtio/virtgpu_ioctl.c b/drivers/gpu/drm/virtio/virtgpu_ioctl.c index c33c057365f8..d0c4edf1eaf4 100644 --- a/drivers/gpu/drm/virtio/virtgpu_ioctl.c +++ b/drivers/gpu/drm/virtio/virtgpu_ioctl.c@@ -489,6 +489,11 @@ static int verify_blob(struct virtio_gpu_device *vgdev, params->size = rc_blob->size; params->blob = true; params->blob_flags = rc_blob->blob_flags; + + if (vgdev->has_blob_alignment && + !IS_ALIGNED(params->size, vgdev->blob_alignment)) + return -EINVAL; + return 0; } --2.53.0
Attachments
- signature.asc [application/pgp-signature] 228 bytes