drm/vmwgfx: avoid null pointer dereference at failure paths
vmw_takedown_otable_base() and vmw_mob_unbind() check for
potential vmw_fifo_reserve() failure and print error message,
but then immediately dereference NULL pointer.
Found by Linux Driver Verification project (linuxtesting.org).
Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Reviewed-by: Thomas Hellstrom <thellstrom@vmware.com>
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_mob.c b/drivers/gpu/drm/vmwgfx/vmwgfx_mob.c
index d4a5a19..04a64b8 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_mob.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_mob.c
@@ -188,18 +188,20 @@
bo = otable->page_table->pt_bo;
cmd = vmw_fifo_reserve(dev_priv, sizeof(*cmd));
- if (unlikely(cmd == NULL))
- DRM_ERROR("Failed reserving FIFO space for OTable setup.\n");
-
- memset(cmd, 0, sizeof(*cmd));
- cmd->header.id = SVGA_3D_CMD_SET_OTABLE_BASE;
- cmd->header.size = sizeof(cmd->body);
- cmd->body.type = type;
- cmd->body.baseAddress = 0;
- cmd->body.sizeInBytes = 0;
- cmd->body.validSizeInBytes = 0;
- cmd->body.ptDepth = SVGA3D_MOBFMT_INVALID;
- vmw_fifo_commit(dev_priv, sizeof(*cmd));
+ if (unlikely(cmd == NULL)) {
+ DRM_ERROR("Failed reserving FIFO space for OTable "
+ "takedown.\n");
+ } else {
+ memset(cmd, 0, sizeof(*cmd));
+ cmd->header.id = SVGA_3D_CMD_SET_OTABLE_BASE;
+ cmd->header.size = sizeof(cmd->body);
+ cmd->body.type = type;
+ cmd->body.baseAddress = 0;
+ cmd->body.sizeInBytes = 0;
+ cmd->body.validSizeInBytes = 0;
+ cmd->body.ptDepth = SVGA3D_MOBFMT_INVALID;
+ vmw_fifo_commit(dev_priv, sizeof(*cmd));
+ }
if (bo) {
int ret;
@@ -562,11 +564,12 @@
if (unlikely(cmd == NULL)) {
DRM_ERROR("Failed reserving FIFO space for Memory "
"Object unbinding.\n");
+ } else {
+ cmd->header.id = SVGA_3D_CMD_DESTROY_GB_MOB;
+ cmd->header.size = sizeof(cmd->body);
+ cmd->body.mobid = mob->id;
+ vmw_fifo_commit(dev_priv, sizeof(*cmd));
}
- cmd->header.id = SVGA_3D_CMD_DESTROY_GB_MOB;
- cmd->header.size = sizeof(cmd->body);
- cmd->body.mobid = mob->id;
- vmw_fifo_commit(dev_priv, sizeof(*cmd));
if (bo) {
vmw_fence_single_bo(bo, NULL);
ttm_bo_unreserve(bo);
