From patchwork Wed Mar 15 07:18:31 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wei Chen X-Patchwork-Id: 664335 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 68754C7618B for ; Wed, 15 Mar 2023 07:19:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229778AbjCOHTC (ORCPT ); Wed, 15 Mar 2023 03:19:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53990 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229624AbjCOHSr (ORCPT ); Wed, 15 Mar 2023 03:18:47 -0400 Received: from mail-oa1-x34.google.com (mail-oa1-x34.google.com [IPv6:2001:4860:4864:20::34]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B537D1166A; Wed, 15 Mar 2023 00:18:44 -0700 (PDT) Received: by mail-oa1-x34.google.com with SMTP id 586e51a60fabf-17ac5ee3f9cso1217035fac.12; Wed, 15 Mar 2023 00:18:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; t=1678864724; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=Uta/U05GAafaktR9fApAMeVEtX67Kdj3raMR2qMOvbI=; b=PJ2X+ScApxHTebPxeX1bpYuOF7q01B1YjghfwtSX9BrJezCARL3fcJzeYPbRNAqq8Q 7Wm4cm8ceHVNag03pezg+jR1KBV+BtMvS4ujHJcqIhkb3yXOBqhjkYKDv1QXEmyB51li VVPGWnAGUhnxQ+uCEao0OIqcJCr/17LOOKoNWgWYw3zLPcwhp+BC9bE97WvFQK2QbH/G amtOOyJWhny5O1eaoXOfGnJicjORYiZOyDBdytgJobMhSDWhy3pMIAZ0F5UBEWpJYYpT 1XDJZO8xRd0BXGzrMO5waJ8D3Zfc7fL2/VzWD13i8TUXK/I8qwjy74Fi+T+z+J8KCScB etIw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1678864724; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=Uta/U05GAafaktR9fApAMeVEtX67Kdj3raMR2qMOvbI=; b=MFUMnEmI4X9NxEXlFfMYfX9BiXLWLJ5Uu/AbgL65DR1b2XJHiHRqv9P4VotW6eMvbR 70zP3v3J2Q5I2te34ylPg0w7BlU+N8Ogibfmlj/PkTc1VrLjbd4CT8GVgAbheXOVdpua hB4G42LhyNGrSN4z56i4QZLu9HXUMDBc2YFA3vNqr/or8UqkGBucUZX0CxUBn5vVt1gs JIDeZUCCiPL+LFrhXjgDwjqFT8GpQtN7Q6wDl4XGISn1vjA5TqFDLqHOpS8c+SP49Hfu /frcTayMm3bwwE3dYRac+7dGV90XQmY4lbBy44uduMvBZEg7PUYalIE8tWqg4YUQniwa PDZQ== X-Gm-Message-State: AO0yUKVTmdsuT4ttKPD2aykr8PgC3LH1GinTOrewuP+H4ZYBKWdJcjng Vzy3EVl2QmBiuTBPcl8RjnBntfwy6PSzqA== X-Google-Smtp-Source: AK7set+tVtF3UU14jhEuO63/9HB2svaK+oHMY8mRNgtuyokLjZEUYhsRpjZC9RJHiAdfnnYAgpuYCA== X-Received: by 2002:a05:6870:c084:b0:17a:bbbc:71f6 with SMTP id c4-20020a056870c08400b0017abbbc71f6mr1862775oad.55.1678864723793; Wed, 15 Mar 2023 00:18:43 -0700 (PDT) Received: from chcpu13.cse.ust.hk (191host119.mobilenet.cse.ust.hk. [143.89.191.119]) by smtp.gmail.com with ESMTPSA id f59-20020a9d2c41000000b0068bb6043362sm2047437otb.11.2023.03.15.00.18.41 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 15 Mar 2023 00:18:43 -0700 (PDT) From: Wei Chen To: adaplas@gmail.com Cc: deller@gmx.de, linux-fbdev@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, Wei Chen Subject: [PATCH] fbdev: nvidia: Fix potential divide by zero Date: Wed, 15 Mar 2023 07:18:31 +0000 Message-Id: <20230315071831.3833948-1-harperchen1110@gmail.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fbdev@vger.kernel.org variable var->pixclock can be set by user. In case it equals to zero, divide by zero would occur in nvidiafb_set_par. Similar crashes have happened in other fbdev drivers. There is no check and modification on var->pixclock along the call chain to nvidia_check_var and nvidiafb_set_par. We believe it could also be triggered in driver nvidia from user site. Signed-off-by: Wei Chen --- drivers/video/fbdev/nvidia/nvidia.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/video/fbdev/nvidia/nvidia.c b/drivers/video/fbdev/nvidia/nvidia.c index e60a276b4855..ea4ba3dfb96b 100644 --- a/drivers/video/fbdev/nvidia/nvidia.c +++ b/drivers/video/fbdev/nvidia/nvidia.c @@ -764,6 +764,8 @@ static int nvidiafb_check_var(struct fb_var_screeninfo *var, int pitch, err = 0; NVTRACE_ENTER(); + if (!var->pixclock) + return -EINVAL; var->transp.offset = 0; var->transp.length = 0;