5.0-stable review patch. If anyone has any objections, please let me know.
------------------ From: Eric Biggers <ebigg...@google.com> commit 36b6c9ed45afe89045973e8dee1b004dd5372d40 upstream. 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 <rodrigosiqueiram...@gmail.com> Cc: Haneen Mohammed <hamohammed...@gmail.com> Cc: Daniel Vetter <daniel.vet...@ffwll.ch> Cc: Chris Wilson <ch...@chris-wilson.co.uk> Cc: sta...@vger.kernel.org Signed-off-by: Eric Biggers <ebigg...@google.com> Reviewed-by: Chris Wilson <ch...@chris-wilson.co.uk> Reviewed-by: Rodrigo Siqueira <rodrigosiqueiram...@gmail.com> Signed-off-by: Rodrigo Siqueira <rodrigosiqueiram...@gmail.com> Link: https://patchwork.freedesktop.org/patch/msgid/20190226220858.214438-1-ebigg...@kernel.org Signed-off-by: Maxime Ripard <maxime.rip...@bootlin.com> Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org> --- drivers/gpu/drm/vkms/vkms_gem.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) --- a/drivers/gpu/drm/vkms/vkms_gem.c +++ b/drivers/gpu/drm/vkms/vkms_gem.c @@ -111,11 +111,8 @@ struct drm_gem_object *vkms_gem_create(s ret = drm_gem_handle_create(file, &obj->gem, handle); drm_gem_object_put_unlocked(&obj->gem); - if (ret) { - drm_gem_object_release(&obj->gem); - kfree(obj); + if (ret) return ERR_PTR(ret); - } return &obj->gem; }