| From c9912b3d72b39e1cb63c569f483db8040c8d924e Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Wed, 4 Jul 2018 12:42:50 +0300 |
| Subject: drm/virtio: fix bounds check in virtio_gpu_cmd_get_capset() |
| |
| From: Dan Carpenter <dan.carpenter@oracle.com> |
| |
| [ Upstream commit 09c4b49457434fa74749ad6194ef28464d9f5df9 ] |
| |
| This doesn't affect runtime because in the current code "idx" is always |
| valid. |
| |
| First, we read from "vgdev->capsets[idx].max_size" before checking |
| whether "idx" is within bounds. And secondly the bounds check is off by |
| one so we could end up reading one element beyond the end of the |
| vgdev->capsets[] array. |
| |
| Fixes: 62fb7a5e1096 ("virtio-gpu: add 3d/virgl support") |
| Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> |
| Link: http://patchwork.freedesktop.org/patch/msgid/20180704094250.m7sgvvzg3dhcvv3h@kili.mountain |
| Signed-off-by: Gerd Hoffmann <kraxel@redhat.com> |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| drivers/gpu/drm/virtio/virtgpu_vq.c | 5 +++-- |
| 1 file changed, 3 insertions(+), 2 deletions(-) |
| |
| diff --git a/drivers/gpu/drm/virtio/virtgpu_vq.c b/drivers/gpu/drm/virtio/virtgpu_vq.c |
| index a1b3ea1ccb65b..772a5a3b0ce1a 100644 |
| --- a/drivers/gpu/drm/virtio/virtgpu_vq.c |
| +++ b/drivers/gpu/drm/virtio/virtgpu_vq.c |
| @@ -681,11 +681,11 @@ int virtio_gpu_cmd_get_capset(struct virtio_gpu_device *vgdev, |
| { |
| struct virtio_gpu_get_capset *cmd_p; |
| struct virtio_gpu_vbuffer *vbuf; |
| - int max_size = vgdev->capsets[idx].max_size; |
| + int max_size; |
| struct virtio_gpu_drv_cap_cache *cache_ent; |
| void *resp_buf; |
| |
| - if (idx > vgdev->num_capsets) |
| + if (idx >= vgdev->num_capsets) |
| return -EINVAL; |
| |
| if (version > vgdev->capsets[idx].max_version) |
| @@ -695,6 +695,7 @@ int virtio_gpu_cmd_get_capset(struct virtio_gpu_device *vgdev, |
| if (!cache_ent) |
| return -ENOMEM; |
| |
| + max_size = vgdev->capsets[idx].max_size; |
| cache_ent->caps_cache = kmalloc(max_size, GFP_KERNEL); |
| if (!cache_ent->caps_cache) { |
| kfree(cache_ent); |
| -- |
| 2.20.1 |
| |
