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 X-Spam-Level: X-Spam-Status: No, score=-15.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 2B2E3C432BE for ; Wed, 11 Aug 2021 13:46:24 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id D920760FD9 for ; Wed, 11 Aug 2021 13:46:22 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org D920760FD9 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 4D404893D0; Wed, 11 Aug 2021 13:46:22 +0000 (UTC) Received: from mail-pl1-x62d.google.com (mail-pl1-x62d.google.com [IPv6:2607:f8b0:4864:20::62d]) by gabe.freedesktop.org (Postfix) with ESMTPS id BA02289836; Wed, 11 Aug 2021 11:35:43 +0000 (UTC) Received: by mail-pl1-x62d.google.com with SMTP id e15so2266120plh.8; Wed, 11 Aug 2021 04:35:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=ocNu8t+0vPe8xDuDrmXUgxK/R5Hfv7t0v2kfkL1QOgA=; b=B+dx6gtSem9LSUSvN8E6giOkQHucQX2rfdWvdRiGZVmSPgioJxHNzz96Wv/7YAzK/m JyrlpDgL5bOF6eMtXkydeAbLGqIVrhMrKIOcRV1PJmBbaTyLJ7prchjvpW3b/9EJ4Gcf ateFz6QnoBeY6tSGD7pStGh857XyHpTJPAPNYmXPvvaf8f6DMcrxqyD04zVorltoKP3z E9/BFvyIJiHW/R/cj3ZR88UE93OebnOpVaMGRh8SMPHgat07me51s6HqtWI7CNWbMEe0 xEtnFJU2f52n+5cz37RdDZfaSwfAZp2z2D4FqRC4OCW3n6bDmRvJZFMhXfWD/Tci4rTh 0rZA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=ocNu8t+0vPe8xDuDrmXUgxK/R5Hfv7t0v2kfkL1QOgA=; b=uSzWJV/eezSxder5xeW2IWtL58T22pc0rawYu8az8YGJuTSwoW6HQn34lrDTFU8i1k t6SR+BeuuuuM9TUbR8R6YHU5gh+1OibyrUh/pcYs4Ts/ModE9w9j5aj2EHFwwGndYWw8 WzilqUHWRbgk8KT40nBAJpZFRKzS7TJkSehoC2pmE7uCMECrsa5gaPgGD8a3ThOyzjTV PeQEGWSyK1bLwanMdUfyLAkqRaAxTOjtbhx3nPIcVgwcNjKrv+h5CC3z6vdpOProyuoW s8OXGMYDrl/htM8TpjBsQ2jZtRR/dpOYtbZbO3abxufR4VDJ0OFUMwnlq7AodhbXAPV4 v8ug== X-Gm-Message-State: AOAM531csZKWm9wz7LhBB8V1pGz2aZJd8PVICXY1ZgkpanoW5CHUSj7W iAB3CwEToen9qMbuuP8ri30= X-Google-Smtp-Source: ABdhPJz2SBVANXMZ07VbSSh4pznTgoL/y9wtPx7R4CwSyd5hF9Ctj75Fuud9mXAdwAvfcZj7S9//6A== X-Received: by 2002:a17:902:8543:b029:12d:461f:a6a8 with SMTP id d3-20020a1709028543b029012d461fa6a8mr3905116plo.1.1628681743298; Wed, 11 Aug 2021 04:35:43 -0700 (PDT) Received: from localhost.localdomain ([45.135.186.103]) by smtp.gmail.com with ESMTPSA id c12sm26423669pfl.56.2021.08.11.04.35.39 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 11 Aug 2021 04:35:42 -0700 (PDT) From: Tuo Li To: alexander.deucher@amd.com, christian.koenig@amd.com, Xinhui.Pan@amd.com, airlied@linux.ie, daniel@ffwll.ch, luben.tuikov@amd.com, tzimmermann@suse.de, sam@ravnborg.org Cc: amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, baijiaju1990@gmail.com, Tuo Li , TOTE Robot Subject: [PATCH] gpu: drm: amd: amdgpu: amdgpu_i2c: fix possible uninitialized-variable access in amdgpu_i2c_router_select_ddc_port() Date: Wed, 11 Aug 2021 04:34:58 -0700 Message-Id: <20210811113458.6940-1-islituo@gmail.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Mailman-Approved-At: Wed, 11 Aug 2021 13:46:15 +0000 X-BeenThere: amd-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Discussion list for AMD gfx List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: amd-gfx-bounces@lists.freedesktop.org Sender: "amd-gfx" 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 --- 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; -- 2.25.1