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 17228C61DD3 for ; Mon, 31 Aug 2026 21:56:49 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 3CB3310E0CC; Mon, 31 Aug 2026 21:56:48 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.b="Qb2vxoAO"; 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 DFBE610E0CC for ; Mon, 31 Aug 2026 21:56:46 +0000 (UTC) Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id 17E2A601DE for ; Mon, 31 Aug 2026 21:56:46 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 941111F000E9; Mon, 31 Aug 2026 21:56:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788213405; bh=eQGwF3SNgNcDvDsU9vMR14pU7TZdrVUyF7CPvmfWfsQ=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=Qb2vxoAOvmKB6vDLImYHdXPp4HpLP11Ta+FOSVrfA8Dv++lCIwR+Ma9L+LluIZRWY B/+jjCwlRD4wIwnC3in51kzZdz0sSzomgEfGFdOkGsnrpcdv04m9XyaY0ETR6fIaqP y1kaKDOXDvUMux92a+jOvyGfoYcaW8an1DgyxW6JkS5HAZ9wfKOnwQFp99gGNOyxWb KCeZxKzHzUCHwo9l8NRm5ugqHgj0ZuhmNvr8M9GQHcOwZ4wcHbXEiQfOIMtrXrytUF pvTLWwwJMKkUNaM/U8FX5sA3UhVUZGixYKn0UYND2XpaY0UQ3zsmPMtTlV9jdsCiGW VezMnRScPZF4g== From: sashiko-bot@kernel.org Subject: Re: [PATCH v3 28/40] drm/atmel-hlcdc: Convert to atomic_create_state To: "Maxime Ripard" Cc: dri-devel@lists.freedesktop.org In-Reply-To: <20260831-drm-no-more-plane-reset-v3-28-1877c7aa57b3@kernel.org> References: <20260831-drm-no-more-plane-reset-v3-0-1877c7aa57b3@kernel.org> <20260831-drm-no-more-plane-reset-v3-28-1877c7aa57b3@kernel.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Mon, 31 Aug 2026 21:56:45 +0000 Message-Id: <20260831215645.941111F000E9@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] A NULL pointer dereference occurs in atmel_hlcdc_plane_atomic_dupl= icate_state if plane->state is NULL. -- commit 004bf4e4c17577d951c839204e87ff451eddcce3 Author: Maxime Ripard drm/atmel-hlcdc: Convert to atomic_create_state This commit converts the plane reset implementation to use the standard atomic_create_state hook. The change was generated using a Coccinelle semantic patch to automate the transformation. > diff --git a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_plane.c b/drivers/gp= u/drm/atmel-hlcdc/atmel_hlcdc_plane.c > index 70a1cef24388f..e09ce6342085d 100644 > --- a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_plane.c > +++ b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_plane.c > @@ -1183,31 +1183,31 @@ static void atmel_hlcdc_plane_atomic_destroy_stat= e(struct drm_plane *p, [ ... ] > -static void atmel_hlcdc_plane_reset(struct drm_plane *p) > +static struct drm_plane_state *atmel_hlcdc_plane_create_state(struct drm= _plane *p) > { > struct atmel_hlcdc_plane_state *state; > - > - if (p->state) { > - atmel_hlcdc_plane_atomic_destroy_state(p, p->state); > - p->state =3D NULL; > - } > + int ret; > =20 > state =3D kzalloc_obj(*state); > - if (state) { > - if (atmel_hlcdc_plane_alloc_dscrs(p, state)) { > - kfree(state); > - drm_err(p->dev, > - "Failed to allocate initial plane state\n"); > - return; > - } > - __drm_atomic_helper_plane_reset(p, &state->base); > + if (!state) > + return ERR_PTR(-ENOMEM); [Severity: High] This is a pre-existing issue, but could a failure here cause a NULL pointer dereference later? If this initial allocation fails during device probe or reset, the DRM core leaves p->state as NULL. When a subsequent atomic modeset is initiated, the core calls the driver's atomic_duplicate_state hook. In atmel_hlcdc_plane_atomic_duplicate_state(), this NULL state is retrieved: struct atmel_hlcdc_plane_state *state =3D drm_plane_state_to_atmel_hlcdc_plane_state(p->state); And then directly passed to kmemdup(): copy =3D kmemdup(state, sizeof(*state), GFP_KERNEL); Since kmemdup() does not check for a NULL source pointer, this leads to a kernel panic inside its internal memcpy() call. --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20260831-drm-no-mor= e-plane-reset-v3-0-1877c7aa57b3@kernel.org?part=3D28