From nobody Fri Oct 31 09:43:42 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) client-ip=192.237.175.120; envelope-from=xen-devel-bounces@lists.xenproject.org; helo=lists.xenproject.org; Authentication-Results: mx.zohomail.com; spf=pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org; dmarc=fail(p=none dis=none) header.from=suse.de Return-Path: Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) by mx.zohomail.com with SMTPS id 1749805500423345.8811885869102; Fri, 13 Jun 2025 02:05:00 -0700 (PDT) Received: from list by lists.xenproject.org with outflank-mailman.1013941.1392136 (Exim 4.92) (envelope-from ) id 1uQ0L2-0002PT-KG; Fri, 13 Jun 2025 09:04:40 +0000 Received: by outflank-mailman (output) from mailman id 1013941.1392136; Fri, 13 Jun 2025 09:04:40 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1uQ0L2-0002PK-Ft; Fri, 13 Jun 2025 09:04:40 +0000 Received: by outflank-mailman (input) for mailman id 1013941; Fri, 13 Jun 2025 09:04:38 +0000 Received: from se1-gles-sth1-in.inumbo.com ([159.253.27.254] helo=se1-gles-sth1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1uQ0L0-0002BZ-Gw for xen-devel@lists.xenproject.org; Fri, 13 Jun 2025 09:04:38 +0000 Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.223.130]) by se1-gles-sth1.inumbo.com (Halon) with ESMTPS id 6e808dd8-4835-11f0-a309-13f23c93f187; Fri, 13 Jun 2025 11:04:37 +0200 (CEST) Received: from imap1.dmz-prg2.suse.org (imap1.dmz-prg2.suse.org [IPv6:2a07:de40:b281:104:10:150:64:97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id 0A00521268; Fri, 13 Jun 2025 09:04:37 +0000 (UTC) Received: from imap1.dmz-prg2.suse.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by imap1.dmz-prg2.suse.org (Postfix) with ESMTPS id 785D713A9C; Fri, 13 Jun 2025 09:04:36 +0000 (UTC) Received: from dovecot-director2.suse.de ([2a07:de40:b281:106:10:150:64:167]) by imap1.dmz-prg2.suse.org with ESMTPSA id qH36G6TpS2inNAAAD6G6ig (envelope-from ); Fri, 13 Jun 2025 09:04:36 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 6e808dd8-4835-11f0-a309-13f23c93f187 Authentication-Results: smtp-out1.suse.de; none From: Thomas Zimmermann To: simona@ffwll.ch, airlied@gmail.com, mripard@kernel.org, maarten.lankhorst@linux.intel.com, geert@linux-m68k.org, tomi.valkeinen@ideasonboard.com Cc: dri-devel@lists.freedesktop.org, linux-mediatek@lists.infradead.org, freedreno@lists.freedesktop.org, linux-arm-msm@vger.kernel.org, imx@lists.linux.dev, linux-samsung-soc@vger.kernel.org, nouveau@lists.freedesktop.org, virtualization@lists.linux.dev, spice-devel@lists.freedesktop.org, linux-renesas-soc@vger.kernel.org, linux-rockchip@lists.infradead.org, linux-tegra@vger.kernel.org, intel-xe@lists.freedesktop.org, xen-devel@lists.xenproject.org, Thomas Zimmermann Subject: [PATCH v5 01/25] drm/dumb-buffers: Sanitize output on errors Date: Fri, 13 Jun 2025 11:00:20 +0200 Message-ID: <20250613090431.127087-2-tzimmermann@suse.de> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250613090431.127087-1-tzimmermann@suse.de> References: <20250613090431.127087-1-tzimmermann@suse.de> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Rspamd-Pre-Result: action=no action; module=replies; Message is reply to one we originated X-Rspamd-Server: rspamd2.dmz-prg2.suse.org X-Spam-Level: X-Spamd-Result: default: False [-4.00 / 50.00]; REPLY(-4.00)[] X-Spam-Flag: NO X-Rspamd-Queue-Id: 0A00521268 X-Rspamd-Pre-Result: action=no action; module=replies; Message is reply to one we originated X-Rspamd-Action: no action X-Spam-Score: -4.00 X-ZM-MESSAGEID: 1749805501899116600 Content-Type: text/plain; charset="utf-8" The ioctls MODE_CREATE_DUMB and MODE_MAP_DUMB return results into a memory buffer supplied by user space. On errors, it is possible that intermediate values are being returned. The exact semantics depends on the DRM driver's implementation of these ioctls. Although this is most-likely not a security problem in practice, avoid any uncertainty by clearing the memory to 0 on errors. Signed-off-by: Thomas Zimmermann Reviewed-by: Tomi Valkeinen --- drivers/gpu/drm/drm_dumb_buffers.c | 40 ++++++++++++++++++++++-------- 1 file changed, 29 insertions(+), 11 deletions(-) diff --git a/drivers/gpu/drm/drm_dumb_buffers.c b/drivers/gpu/drm/drm_dumb_= buffers.c index 70032bba1c97..9916aaf5b3f2 100644 --- a/drivers/gpu/drm/drm_dumb_buffers.c +++ b/drivers/gpu/drm/drm_dumb_buffers.c @@ -99,7 +99,30 @@ int drm_mode_create_dumb(struct drm_device *dev, int drm_mode_create_dumb_ioctl(struct drm_device *dev, void *data, struct drm_file *file_priv) { - return drm_mode_create_dumb(dev, data, file_priv); + struct drm_mode_create_dumb *args =3D data; + int err; + + err =3D drm_mode_create_dumb(dev, args, file_priv); + if (err) { + args->handle =3D 0; + args->pitch =3D 0; + args->size =3D 0; + } + return err; +} + +static int drm_mode_mmap_dumb(struct drm_device *dev, struct drm_mode_map_= dumb *args, + struct drm_file *file_priv) +{ + if (!dev->driver->dumb_create) + return -ENOSYS; + + if (dev->driver->dumb_map_offset) + return dev->driver->dumb_map_offset(file_priv, dev, args->handle, + &args->offset); + else + return drm_gem_dumb_map_offset(file_priv, dev, args->handle, + &args->offset); } =20 /** @@ -120,17 +143,12 @@ int drm_mode_mmap_dumb_ioctl(struct drm_device *dev, void *data, struct drm_file *file_priv) { struct drm_mode_map_dumb *args =3D data; + int err; =20 - if (!dev->driver->dumb_create) - return -ENOSYS; - - if (dev->driver->dumb_map_offset) - return dev->driver->dumb_map_offset(file_priv, dev, - args->handle, - &args->offset); - else - return drm_gem_dumb_map_offset(file_priv, dev, args->handle, - &args->offset); + err =3D drm_mode_mmap_dumb(dev, args, file_priv); + if (err) + args->offset =3D 0; + return err; } =20 int drm_mode_destroy_dumb(struct drm_device *dev, u32 handle, --=20 2.49.0