diff options
| -rw-r--r-- | drivers/gpu/drm/exynos/exynos_drm_g2d.c | 17 |
1 files changed, 16 insertions, 1 deletions
diff --git a/drivers/gpu/drm/exynos/exynos_drm_g2d.c b/drivers/gpu/drm/exynos/exynos_drm_g2d.c index fbd13fa..603d842 100644 --- a/drivers/gpu/drm/exynos/exynos_drm_g2d.c +++ b/drivers/gpu/drm/exynos/exynos_drm_g2d.c @@ -1193,6 +1193,17 @@ int exynos_g2d_set_cmdlist_ioctl(struct drm_device *drm_dev, void *data, if (!node) return -ENOMEM; + /* + * To avoid an integer overflow for the later size computations, we + * enforce a maximum number of submitted commands here. This limit is + * sufficient for all conceivable usage cases of the G2D. + */ + if (req->cmd_nr > G2D_CMDLIST_DATA_NUM || + req->cmd_buf_nr > G2D_CMDLIST_DATA_NUM) { + dev_err(dev, "number of submitted G2D commands exceeds limit\n"); + return -EINVAL; + } + node->event = NULL; if (req->event_type != G2D_EVENT_NOT) { @@ -1250,7 +1261,11 @@ int exynos_g2d_set_cmdlist_ioctl(struct drm_device *drm_dev, void *data, cmdlist->data[cmdlist->last++] = G2D_INTEN_ACF; } - /* Check size of cmdlist: last 2 is about G2D_BITBLT_START */ + /* + * Check the size of cmdlist. The 2 that is added last comes from + * the implicit G2D_BITBLT_START that is appended once we have + * checked all the submitted commands. + */ size = cmdlist->last + req->cmd_nr * 2 + req->cmd_buf_nr * 2 + 2; if (size > G2D_CMDLIST_DATA_NUM) { dev_err(dev, "cmdlist size is too big\n"); |