st/mesa: don't dereference stObj->pt if NULL

It seems a user app can get us into this state, I trigger the fail
running fbo-maxsize inside virgl, it fails to create the backing
storage for the texture object, but then segfaults here when it
should fail the completeness test.

Cc: "9.2" <mesa-stable@lists.freedesktop.org>
Reviewed-by: Brian Paul <brianp@vmware.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

diff --git a/src/mesa/state_tracker/st_cb_fbo.c b/src/mesa/state_tracker/st_cb_fbo.c
index 77aaccd0489be1d3f170de1dc7fb8d862059282c..20894825f7fd5a8f0098f61087d08788b381ee0d 100644 (file)
--- a/src/mesa/state_tracker/st_cb_fbo.c
+++ b/src/mesa/state_tracker/st_cb_fbo.c
@@ -502,7 +502,7 @@ st_validate_attachment(struct gl_context *ctx,
    if (att->Type != GL_TEXTURE)
       return GL_TRUE;
 
-   if (!stObj)
+   if (!stObj || !stObj->pt)
       return GL_FALSE;
 
    format = stObj->pt->format;