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 6EFB7C61DFD for ; Mon, 31 Aug 2026 22:58:58 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 957E010E1A0; Mon, 31 Aug 2026 22:58:57 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.b="DAIx9Q/3"; 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 CA8C010E1A0 for ; Mon, 31 Aug 2026 22:58:56 +0000 (UTC) Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id EFC0D601DE for ; Mon, 31 Aug 2026 22:58:55 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 779DC1F000E9; Mon, 31 Aug 2026 22:58:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788217135; bh=TN+AjySWejZuT6KKSaAfH4juJOGwzz3fL1eJ5016p2k=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=DAIx9Q/30cBtHxQaRFsEnt3R7mY08akPuxiagii8xV7VVy9oAzLMscPAcJk/aRtka a2IG99CsWAeOHB3L+zNi49KuIb5GQu4m36ZstcNWHYP+mC6H6I4AmYNFcAdeoH6ate 3oddLrXp1swlH08swxghm0saDnTW3uEs3Y4R8qiyBZ6M01AzpCPyapBGWWuBdL5sxq KxEvgd+kS0jnL1q5wNQs68FLEWZs4rGwoi6ROLOPBgREp1IM23OEsCUIEgSeu3JfXh cqW3K14+3iImU+uKsyEeDep5VW+pvuBcWdBf/WAA+BmE4PuNZDllCgHapFMO8YqjWO 1UrGUX9WdIEGQ== From: sashiko-bot@kernel.org Subject: Re: [PATCH v3 38/40] drm/vmwgfx: Convert to atomic_create_state To: "Maxime Ripard" Cc: dri-devel@lists.freedesktop.org In-Reply-To: <20260831-drm-no-more-plane-reset-v3-38-1877c7aa57b3@kernel.org> References: <20260831-drm-no-more-plane-reset-v3-0-1877c7aa57b3@kernel.org> <20260831-drm-no-more-plane-reset-v3-38-1877c7aa57b3@kernel.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Mon, 31 Aug 2026 22:58:55 +0000 Message-Id: <20260831225855.779DC1F000E9@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] Dangling pointer leading to Use-After-Free in vmw_du_connector_res= et when kzalloc_obj fails. -- commit 0910404d300f75561678f127f981fe7f17dcd288 Author: Maxime Ripard drm/vmwgfx: Convert to atomic_create_state The plane reset implementation creates a custom state subclass, but only initializes a pristine state without resetting any hardware. This is equivalent to what atomic_create_state expects. Convert to it. > diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c b/drivers/gpu/drm/vmwgfx= /vmwgfx_kms.c > index 0b470809661c7..9031dccad31d7 100644 > --- a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c > +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c > @@ -279,27 +279,24 @@ vmw_du_plane_duplicate_state(struct drm_plane *plan= e) > =20 > =20 > /** > - * vmw_du_plane_reset - creates a blank vmw plane state > + * vmw_du_plane_create_state - creates a blank vmw plane state > * @plane: drm plane > * > - * Resets the atomic state for @plane by freeing the state pointer (whic= h might > - * be NULL, e.g. at driver load time) and allocating a new empty state o= bject. > + * Allocates a new empty state object. > */ > -void vmw_du_plane_reset(struct drm_plane *plane) > +struct drm_plane_state *vmw_du_plane_create_state(struct drm_plane *plan= e) > { > struct vmw_plane_state *vps; > =20 > - if (plane->state) > - vmw_du_plane_destroy_state(plane, plane->state); > - > vps =3D kzalloc_obj(*vps); > - > if (!vps) { > DRM_ERROR("Cannot allocate vmw_plane_state\n"); > - return; > + return ERR_PTR(-ENOMEM); > } [Severity: High] This isn't a bug introduced by this patch, but while reviewing this change I noticed a similar pre-existing issue remains in vmw_du_connector_reset(). When kzalloc_obj() fails during memory pressure (e.g., during device probe, modeset, or hotplug handling), connector->state is left dangling as a point= er to the previously freed memory: drivers/gpu/drm/vmwgfx/vmwgfx_kms.c:vmw_du_connector_reset() { if (connector->state) { __drm_atomic_helper_connector_destroy_state(connector->state); kfree(vmw_connector_state_to_vcs(connector->state)); } vcs =3D kzalloc_obj(*vcs); if (!vcs) { DRM_ERROR("Cannot allocate vmw_connector_state\n"); return; } ... } Does this leave connector->state pointing to freed memory, leading to a use-after-free when the DRM core later accesses it? --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20260831-drm-no-mor= e-plane-reset-v3-0-1877c7aa57b3@kernel.org?part=3D38