From nobody Wed Apr 15 05:42:18 2026 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6E276C43334 for ; Mon, 25 Jul 2022 10:46:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234809AbiGYKqE (ORCPT ); Mon, 25 Jul 2022 06:46:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36238 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232638AbiGYKqB (ORCPT ); Mon, 25 Jul 2022 06:46:01 -0400 Received: from mail.ispras.ru (mail.ispras.ru [83.149.199.84]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5ED03313 for ; Mon, 25 Jul 2022 03:46:00 -0700 (PDT) Received: from alisa-ThinkPad-T440s.. (unknown [83.149.199.65]) by mail.ispras.ru (Postfix) with ESMTPS id D00E440D403D; Mon, 25 Jul 2022 10:45:56 +0000 (UTC) From: Alisa Khabibrakhmanova To: David Airlie , Daniel Vetter Cc: Alisa Khabibrakhmanova , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, ldv-project@linuxtesting.org Subject: [PATCH] drm/via: Add new condition to via_dma_cleanup() Date: Mon, 25 Jul 2022 13:45:55 +0300 Message-Id: <20220725104555.124044-1-khabibrakhmanova@ispras.ru> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Pointer dev_priv->mmio, which was checked for NULL at via_do_init_map(), is passed to via_do_cleanup_map() and is dereferenced there without check. The patch adds the condition in via_dma_cleanup() which prevents potential = NULL pointer dereference. Found by Linux Verification Center (linuxtesting.org) with SVACE. Fixes: 22f579c621e2 ("drm: Add via unichrome support") Signed-off-by: Alisa Khabibrakhmanova --- drivers/gpu/drm/via/via_dma.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/via/via_dma.c b/drivers/gpu/drm/via/via_dma.c index 177b0499abf1..56bcbbf4ed54 100644 --- a/drivers/gpu/drm/via/via_dma.c +++ b/drivers/gpu/drm/via/via_dma.c @@ -164,7 +164,7 @@ int via_dma_cleanup(struct drm_device *dev) drm_via_private_t *dev_priv =3D (drm_via_private_t *) dev->dev_private; =20 - if (dev_priv->ring.virtual_start) { + if (dev_priv->ring.virtual_start && dev_priv->mmio) { via_cmdbuf_reset(dev_priv); =20 drm_legacy_ioremapfree(&dev_priv->ring.map, dev); --=20 2.34.1