Quoting Eric Biggers (2019-02-26 22:08:58)
From: Eric Biggers ebiggers@google.com
If drm_gem_handle_create() fails in vkms_gem_create(), then the vkms_gem_object is freed twice: once when the reference is dropped by drm_gem_object_put_unlocked(), and again by the extra calls to drm_gem_object_release() and kfree().
Fix it by skipping the second release and free.
This bug was originally found in the vgem driver by syzkaller using fault injection, but I noticed it's also present in the vkms driver.
Fixes: 559e50fd34d1 ("drm/vkms: Add dumb operations") Cc: Rodrigo Siqueira rodrigosiqueiramelo@gmail.com Cc: Haneen Mohammed hamohammed.sa@gmail.com Cc: Daniel Vetter daniel.vetter@ffwll.ch Cc: Chris Wilson chris@chris-wilson.co.uk Cc: stable@vger.kernel.org Signed-off-by: Eric Biggers ebiggers@google.com
Reviewed-by: Chris Wilson chris@chris-wilson.co.uk -Chris