From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 7F9DBC61DFD for ; Mon, 31 Aug 2026 19:31:15 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id B28B910E818; Mon, 31 Aug 2026 19:31:14 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.b="YO4V6WjJ"; dkim-atps=neutral Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by gabe.freedesktop.org (Postfix) with ESMTPS id 19A3910E818 for ; Mon, 31 Aug 2026 19:31:14 +0000 (UTC) Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id 4846A601DE for ; Mon, 31 Aug 2026 19:31:13 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C7C0F1F000E9; Mon, 31 Aug 2026 19:31:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788204673; bh=GMUkLy9MMovLUBCW1EjwPW8tvpfn5z3f/1esx7mK0c8=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=YO4V6WjJdluhrAmiXDh5Dqor+oQsKZZpikDgbCfhxA47EGJ7WTnezHXIFS/VAsard JqxS0HEvpMV7K4EAZ0mAsH6q6A2B6YpGL9YUQ74USC3f4y5TvHgwWMHAt1ofXHo8Pk 9jPnBVKUH8ZhbyN8Q7Q2NCKjzJyu9u6eCQ3B6UEeFSQHSo6Goz1lPuHrRQ1ornf3KP dM1WMSAj2qtyPyPAWfrHpz45go3ooYVCvbTRirna7eRwH5zkAj4VhouVooHfNJJpol YtPDKYy/Y8n3ogd9WSui5aQfu9faFfj5WzDRaWEa5XFC1N+5nPvpE9P9cNWXkcALFu fUTWBjQuHbk2w== From: sashiko-bot@kernel.org Subject: Re: [PATCH v3 06/40] drm/hisilicon/kirin: Convert to atomic_create_state To: "Maxime Ripard" Cc: dri-devel@lists.freedesktop.org In-Reply-To: <20260831-drm-no-more-plane-reset-v3-6-1877c7aa57b3@kernel.org> References: <20260831-drm-no-more-plane-reset-v3-0-1877c7aa57b3@kernel.org> <20260831-drm-no-more-plane-reset-v3-6-1877c7aa57b3@kernel.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Mon, 31 Aug 2026 19:31:12 +0000 Message-Id: <20260831193112.C7C0F1F000E9@smtp.kernel.org> X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: sashiko-reviews@lists.linux.dev Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Thank you for your contribution! Sashiko AI review found 1 potential issue(= s) to consider: Pre-existing issues: - [High] Use-After-Free during driver cleanup due to premature freeing of D= RM mode objects embedded in `struct kirin_drm_private`. -- commit 263cd9f02efa601fc3d304e38a61e0c61ac2a73e Author: Maxime Ripard drm/hisilicon/kirin: Convert to atomic_create_state The plane only initializes a pristine state in its reset hook using drm_atomic_helper_plane_reset(), which is equivalent to what atomic_create_state expects. Convert to it. [ ... ] > diff --git a/drivers/gpu/drm/hisilicon/kirin/kirin_drm_ade.c b/drivers/gp= u/drm/hisilicon/kirin/kirin_drm_ade.c > index 5f4e738bc94e3..bca839dd600bd 100644 > --- a/drivers/gpu/drm/hisilicon/kirin/kirin_drm_ade.c > +++ b/drivers/gpu/drm/hisilicon/kirin/kirin_drm_ade.c > @@ -837,7 +837,7 @@ static struct drm_plane_funcs ade_plane_funcs =3D { > .update_plane =3D drm_atomic_helper_update_plane, > .disable_plane =3D drm_atomic_helper_disable_plane, > .destroy =3D drm_plane_cleanup, > - .reset =3D drm_atomic_helper_plane_reset, > + .atomic_create_state =3D drm_atomic_helper_plane_create_state, > .atomic_duplicate_state =3D drm_atomic_helper_plane_duplicate_state, > .atomic_destroy_state =3D drm_atomic_helper_plane_destroy_state, > }; [Severity: High] This isn't a bug introduced by this patch, but while reviewing the kirin DRM driver, I noticed a pre-existing use-after-free issue during driver cleanup. In drivers/gpu/drm/hisilicon/kirin/kirin_drm_drv.c, kirin_drm_private_cleanup() frees the memory backing the DRM planes and CRT= Cs: drivers/gpu/drm/hisilicon/kirin/kirin_drm_drv.c:kirin_drm_private_cleanup()= { ... devm_kfree(dev->dev, kirin_priv); ... } However, both the initialization error path and the unbind path call this cleanup before drm_mode_config_cleanup(): drivers/gpu/drm/hisilicon/kirin/kirin_drm_drv.c:kirin_drm_kms_init() { ... err_private_cleanup: kirin_drm_private_cleanup(dev); err_mode_config_cleanup: drm_mode_config_cleanup(dev); ... } The same pattern appears in the unbind path: drivers/gpu/drm/hisilicon/kirin/kirin_drm_drv.c:kirin_drm_kms_cleanup() { ... kirin_drm_private_cleanup(dev); drm_mode_config_cleanup(dev); ... } Can this lead to a use-after-free? When drm_mode_config_cleanup() executes,= it iterates over dev->mode_config.plane_list and accesses the plane objects embedded in the kirin_priv structure that was just freed by devm_kfree(). Additionally, since the structure is devm-managed, could userspace holding = the DRM file descriptor open trigger a use-after-free if the DRM core accesses = the freed objects after unbind completes? --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20260831-drm-no-mor= e-plane-reset-v3-0-1877c7aa57b3@kernel.org?part=3D6