From patchwork Thu Sep 16 16:00:44 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 513661 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DE8C7C433F5 for ; Thu, 16 Sep 2021 17:34:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C914861056 for ; Thu, 16 Sep 2021 17:34:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244236AbhIPRff (ORCPT ); Thu, 16 Sep 2021 13:35:35 -0400 Received: from mail.kernel.org ([198.145.29.99]:50284 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1343959AbhIPRcU (ORCPT ); Thu, 16 Sep 2021 13:32:20 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 71C7D61A6E; Thu, 16 Sep 2021 16:47:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1631810863; bh=taatuuLuDBoBSsvAWC34YtQ3EAR1kJj2dTPwEIz+LIE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=VrGivcZCFT78HuSqOtRdB5yZNoiOL6glJy8yEMOgueLeVWR8o7LfJDJNKxLNXx9G/ 3BcdwJ1lsC2X4jr+NtpG/uq9mMBNwCLeLe3fX+C9d9CNOH/b9KEPs225pz2qzG07ie s+KZCWnvYysBZ7Q6VJKyrLOa04pmW755maEz8rqY= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, TOTE Robot , Tuo Li , Alex Deucher , Sasha Levin Subject: [PATCH 5.14 295/432] gpu: drm: amd: amdgpu: amdgpu_i2c: fix possible uninitialized-variable access in amdgpu_i2c_router_select_ddc_port() Date: Thu, 16 Sep 2021 18:00:44 +0200 Message-Id: <20210916155820.832512449@linuxfoundation.org> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20210916155810.813340753@linuxfoundation.org> References: <20210916155810.813340753@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Tuo Li [ Upstream commit a211260c34cfadc6068fece8c9e99e0fe1e2a2b6 ] The variable val is declared without initialization, and its address is passed to amdgpu_i2c_get_byte(). In this function, the value of val is accessed in: DRM_DEBUG("i2c 0x%02x 0x%02x read failed\n", addr, *val); Also, when amdgpu_i2c_get_byte() returns, val may remain uninitialized, but it is accessed in: val &= ~amdgpu_connector->router.ddc_mux_control_pin; To fix this possible uninitialized-variable access, initialize val to 0 in amdgpu_i2c_router_select_ddc_port(). Reported-by: TOTE Robot Signed-off-by: Tuo Li Signed-off-by: Alex Deucher Signed-off-by: Sasha Levin --- drivers/gpu/drm/amd/amdgpu/amdgpu_i2c.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_i2c.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_i2c.c index bca4dddd5a15..82608df43396 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_i2c.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_i2c.c @@ -339,7 +339,7 @@ static void amdgpu_i2c_put_byte(struct amdgpu_i2c_chan *i2c_bus, void amdgpu_i2c_router_select_ddc_port(const struct amdgpu_connector *amdgpu_connector) { - u8 val; + u8 val = 0; if (!amdgpu_connector->router.ddc_valid) return;