From nobody Tue Sep 16 23:55:20 2025 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 89FD2C4167B for ; Mon, 26 Dec 2022 18:12:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232245AbiLZSME (ORCPT ); Mon, 26 Dec 2022 13:12:04 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35572 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231422AbiLZSLk (ORCPT ); Mon, 26 Dec 2022 13:11:40 -0500 Received: from exchange.fintech.ru (e10edge.fintech.ru [195.54.195.159]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5C582218B for ; Mon, 26 Dec 2022 10:11:35 -0800 (PST) Received: from Ex16-01.fintech.ru (10.0.10.18) by exchange.fintech.ru (195.54.195.169) with Microsoft SMTP Server (TLS) id 14.3.498.0; Mon, 26 Dec 2022 21:10:28 +0300 Received: from localhost (10.0.253.157) by Ex16-01.fintech.ru (10.0.10.18) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2242.4; Mon, 26 Dec 2022 21:10:28 +0300 From: Nikita Zhandarovich To: Alex Deucher CC: Nikita Zhandarovich , =?UTF-8?q?Christian=20K=C3=B6nig?= , "Pan, Xinhui" , Daniel Vetter , , , , Subject: [PATCH] drm/radeon: Fix potential null-ptr-deref Date: Mon, 26 Dec 2022 10:10:23 -0800 Message-ID: <20221226181023.86196-1-n.zhandarovich@fintech.ru> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Originating-IP: [10.0.253.157] X-ClientProxiedBy: Ex16-01.fintech.ru (10.0.10.18) To Ex16-01.fintech.ru (10.0.10.18) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" radeon_get_connector_for_encoder() assigns radeon_encoder->enc_priv to mst_enc which is dereferenced later without being checked for NULL beforehand. It is possible for radeon_encoder->enc_priv and therefore mst_enc, to be NULL due to potential lack of memory. This patch adds a sanity NULL-check to prevent the issue. Found by Linux Verification Center (linuxtesting.org) with SVACE. Fixes: 9843ead08f18 ("drm/radeon: add DisplayPort MST support (v2)") Signed-off-by: Nikita Zhandarovich --- drivers/gpu/drm/radeon/radeon_encoders.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/gpu/drm/radeon/radeon_encoders.c b/drivers/gpu/drm/rad= eon/radeon_encoders.c index 46549d5179ee..3f68f0af443a 100644 --- a/drivers/gpu/drm/radeon/radeon_encoders.c +++ b/drivers/gpu/drm/radeon/radeon_encoders.c @@ -251,6 +251,9 @@ radeon_get_connector_for_encoder(struct drm_encoder *en= coder) continue; =20 mst_enc =3D radeon_encoder->enc_priv; + if (!mst_enc) + return NULL; + if (mst_enc->connector =3D=3D radeon_connector->mst_port) return connector; } else if (radeon_encoder->active_device & radeon_connector->devices) --=20 2.25.1