drm/virtio: fix bounds check in virtio_gpu_cmd_get_capset()

[ 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>
This commit is contained in:
Dan Carpenter 2018-07-04 12:42:50 +03:00 committed by Greg Kroah-Hartman
parent af266e1fd4
commit 2b85c83c6e

View File

@ -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);