Received: by 2002:a05:6358:4e97:b0:b3:742d:4702 with SMTP id ce23csp670227rwb; Thu, 11 Aug 2022 08:04:38 -0700 (PDT) X-Google-Smtp-Source: AA6agR5LIAA+3R1th5zkSoewMrGHoxyvngxRRgZelfhPvHYRC+tcrD9SrZjgj429aku7s6FqCO4b X-Received: by 2002:a17:907:1688:b0:730:b3ae:347 with SMTP id hc8-20020a170907168800b00730b3ae0347mr24721124ejc.756.1660230278760; Thu, 11 Aug 2022 08:04:38 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1660230278; cv=none; d=google.com; s=arc-20160816; b=b7UxHXuLvLW6jxgFRa0EnxeIBibqxd2CM/cE29axVbq9jD9NRyZ0h38BOwwp7nJDf/ ROWHw2Z8RFQuvrTZgaT3g9SA4LnJBO5QWkcEkje90Ud7mO+4/6au/lPkH82LwFHwnmBH rgHy9792pIAXr2QEZeT85lP7ty1snDSl2KUJwH8PgWAiHmJX9dvR1q9+NStXXnNMbxna HZRbIX8g2ISwQ62o6UIWxt0f0terNKREml7MYtzhg/X2ZFYXW5lt0jeiYqQf8kDZrZY1 bnDaVdAoOdgO+YnByZVCyxMyhcz4xgVc1VHZSv/h0OK15600gmEszBXkCVziuTTsSUvC jyzw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :message-id:date:subject:cc:to:from; bh=z7198/Y9cuDxnZtKHbhFqso/faDsv3w2REdJRj6E61s=; b=q3f5nIhahPJNhOssdVHf2hitGl1h4AU7QN4xG9l0o6U2mw+voskOMvQ8q8MZnrDDmX /M3qTDt6XWrKOPh6PgIn7sRZC5SOX8WRvFg4Xca/5hbgnzANr7D9FiaslE1Dhyae+mgZ 8tmOZTp+tGDyxlmBxzUCTnKTDjVSAo4REMNeSu/zmLAAgpfYOlhylE87Isum7hJLj+gb uB4kdFxqZAIniYJPEzh3XQ8XMNQxXXV7YEoSTQZEa9peGYT/G98HsZ7AJUDzj6S2XkQ4 qg8UHjlp52xhFpq71Rjv0tP5iYWqvnIhNdrpdi9Zl7vxStDCKqxi4SWc2iRAjoQEZ2Rj uU5A== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=ispras.ru Return-Path: Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id q20-20020a170906b29400b00730ba32de19si586821ejz.117.2022.08.11.08.04.04; Thu, 11 Aug 2022 08:04:38 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=ispras.ru Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234999AbiHKOtQ (ORCPT + 99 others); Thu, 11 Aug 2022 10:49:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35096 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229594AbiHKOtP (ORCPT ); Thu, 11 Aug 2022 10:49:15 -0400 Received: from mail.ispras.ru (mail.ispras.ru [83.149.199.84]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6B1FC90802 for ; Thu, 11 Aug 2022 07:49:13 -0700 (PDT) Received: from localhost.localdomain (unknown [83.149.199.65]) by mail.ispras.ru (Postfix) with ESMTPS id BD73640D403E; Thu, 11 Aug 2022 14:49:10 +0000 (UTC) From: Andrey Strachuk To: Maarten Lankhorst Cc: Andrey Strachuk , Maxime Ripard , Thomas Zimmermann , David Airlie , Daniel Vetter , Geert Uytterhoeven , Helge Deller , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, ldv-project@linuxtesting.org Subject: [PATCH v2] drm/fb-helper: add virtual screen size check to drm_fb_helper_check_var() Date: Thu, 11 Aug 2022 17:48:50 +0300 Message-Id: <20220811144850.215377-1-strochuk@ispras.ru> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00,SPF_HELO_NONE, SPF_PASS,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Add virtual screen size check to drm_fb_helper_check_var() in order to validate userspace input. Found by Linux Verification Center (linuxtesting.org) with syzkaller. Signed-off-by: Andrey Strachuk Fixes: 785b93ef8c30 ("drm/kms: move driver specific fb common code to helper functions (v2)") --- drivers/gpu/drm/drm_fb_helper.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c index 2d4cee6a10ff..5c8b211769eb 100644 --- a/drivers/gpu/drm/drm_fb_helper.c +++ b/drivers/gpu/drm/drm_fb_helper.c @@ -1355,6 +1355,12 @@ int drm_fb_helper_check_var(struct fb_var_screeninfo *var, (drm_format_info_block_height(fb->format, 0) > 1)) return -EINVAL; + /* verify that virtual resolution >= physical resolution */ + if (var->xres_virtual < var->xres) + var->xres_virtual = var->xres; + if (var->yres_virtual < var->yres) + var->yres_virtual = var->yres; + /* * Changes struct fb_var_screeninfo are currently not pushed back * to KMS, hence fail if different settings are requested. -- 2.25.1