From patchwork Wed Feb 2 23:33:58 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yizhuo Zhai X-Patchwork-Id: 539476 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 CC85FC433EF for ; Wed, 2 Feb 2022 23:33:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1348078AbiBBXd5 (ORCPT ); Wed, 2 Feb 2022 18:33:57 -0500 Received: from mx-lax3-2.ucr.edu ([169.235.156.37]:60219 "EHLO mx-lax3-2.ucr.edu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1347732AbiBBXd4 (ORCPT ); Wed, 2 Feb 2022 18:33:56 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=ucr.edu; i=@ucr.edu; q=dns/txt; s=selector3; t=1643844836; x=1675380836; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=uavpFDxmGoKjrnyH0fVmnFMq2r7aGr052ubiJDv8DR8=; b=ZsxCq6VOaQejAGfXqnHIWmlwIuEB4pxItn+JB1W4ncCaPhZ2r2IBXdh4 2kZteC8ShzrpOIU9vHkDHQ7n2Bdn2sldRgIKGJQmkfp7sV3d3Et63NvKO 8pszNq3npGUncSCLRbHO63Rcedsyob3CCFOpEYOHZtp0wVFJtbvKZ3/mx INZ9pL0UhkI62EGNbEmqa77Gg2ZpX3mNDJGO5yAfsJWFHtPVuE6BgkbI5 bZUj951b8czRPlvVmXulBRxA66yzhYIcPdpO/ZaT0ethyWvPV+mXAxqWi PeoS+8BnJ9menTwL4hSSOuKjjfgvUo6H9UMKIO+ioZCVdiEa17R8+a0/O Q==; X-IronPort-AV: E=Sophos;i="5.88,338,1635231600"; d="scan'208";a="102067139" Received: from mail-pj1-f69.google.com ([209.85.216.69]) by smtp-lax3-2.ucr.edu with ESMTP/TLS/ECDHE-RSA-AES128-GCM-SHA256; 02 Feb 2022 15:33:55 -0800 Received: by mail-pj1-f69.google.com with SMTP id mg17-20020a17090b371100b001b816f127e0so4710927pjb.9 for ; Wed, 02 Feb 2022 15:33:56 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ucr.edu; s=rmail; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=LoPhiSf2j9AFlf81eKG6xH4TR1F1QmboBbxydv3xQ7Y=; b=xDmZHe7b0lAJqRV03cgiwQiq8aVyFS9aT+B3OaOw+dR+d9mfsO5WhWIS1hey9PxQ/8 pnHAutlDAUGni9R+QOz9ct54DuHYBVVF5lAGy+MaQvBMrHnR7tpJyTD+Ji0/d05HnW3U zPGVsGrgSzCJ8Zj7ELBZ7A+GpZsIoy7zxD5Ms= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=LoPhiSf2j9AFlf81eKG6xH4TR1F1QmboBbxydv3xQ7Y=; b=4woc++xisrQTisd2SgLXSP7YKMn/we6G+cHmFgEFUg0wPS234rlyluy9VvCceZuGWz DuMJNBvf4Tfy2900Qg1a3cbgY6+L6k10DiigqrXms1JI8smJ2ymFn1NvIYhzRdIt99ul 2j6wxIliFe+BwqNU5dbodliBk1D4Yx9NgRlit6st6UZzn1NAfC05Pn6ZLPKobK4KwUrV U9PZGD/9KypyM0tiP8W5FLPdBYgHV/XzMEZCApPvvTnVMgu0W6bM6x1G4z1xkGtuDw2X HmEomGrlb59b2oUL4Cg1UIK1I1ulUwLThlFcqbWYycXLn9Wl8oO7doz6HxiiGLypppA0 lmjQ== X-Gm-Message-State: AOAM530WgYDRKXMOTMuUqpXgXdjORqQriuBsxCkoNMy9cL+LMtaMkrM2 5oKHWmfA/xlyeqTj+TJ0tAHMMKPcuMbTpeaKFe3uTlNUjhP+104CfxWYAypr3NIs90wskdDxRbT wFa5Fr2UOrVsmmQ8dkI2Q3gNY X-Received: by 2002:a17:90b:3841:: with SMTP id nl1mr10901906pjb.50.1643844835697; Wed, 02 Feb 2022 15:33:55 -0800 (PST) X-Google-Smtp-Source: ABdhPJwKw43I55RvXKUF5Oc0gQfOIu6GaU+jb9Uz6QfMkQXdHo2WKNl3sIP6kqSgU/6tvpMjh2bLug== X-Received: by 2002:a17:90b:3841:: with SMTP id nl1mr10901883pjb.50.1643844835458; Wed, 02 Feb 2022 15:33:55 -0800 (PST) Received: from kq.cs.ucr.edu (kq.cs.ucr.edu. [169.235.27.223]) by smtp.googlemail.com with ESMTPSA id s2sm26380387pgq.38.2022.02.02.15.33.54 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 02 Feb 2022 15:33:55 -0800 (PST) From: Yizhuo Zhai Cc: Yizhuo Zhai , Helge Deller , Daniel Vetter , Matthew Wilcox , Sam Ravnborg , Tetsuo Handa , Zhen Lei , Zheyu Ma , Alex Deucher , Xiyu Yang , Guenter Roeck , linux-fbdev@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Subject: [PATCH v5] fbdev: fbmem: Fix the implicit type casting Date: Wed, 2 Feb 2022 15:33:58 -0800 Message-Id: <20220202233402.1477864-1-yzhai003@ucr.edu> X-Mailer: git-send-email 2.25.1 In-Reply-To: <83e46d8d-ec7a-6cbd-010e-7f50f88dcf96@I-love.SAKURA.ne.jp> References: <83e46d8d-ec7a-6cbd-010e-7f50f88dcf96@I-love.SAKURA.ne.jp> MIME-Version: 1.0 To: unlisted-recipients:; (no To-header on input) Precedence: bulk List-ID: X-Mailing-List: linux-fbdev@vger.kernel.org In function do_fb_ioctl(), the "arg" is the type of unsigned long, and in "case FBIOBLANK:" this argument is casted into an int before passig to fb_blank(). In fb_blank(), the comparision if (blank > FB_BLANK_POWERDOWN) would be bypass if the original "arg" is a large number, which is possible because it comes from the user input. Fix this by adding the check before the function call. Signed-off-by: Yizhuo Zhai --- drivers/video/fbdev/core/fbmem.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/video/fbdev/core/fbmem.c b/drivers/video/fbdev/core/fbmem.c index 0fa7ede94fa6..d5dec24c4d16 100644 --- a/drivers/video/fbdev/core/fbmem.c +++ b/drivers/video/fbdev/core/fbmem.c @@ -1162,6 +1162,11 @@ static long do_fb_ioctl(struct fb_info *info, unsigned int cmd, case FBIOBLANK: console_lock(); lock_fb_info(info); + if (arg > FB_BLANK_POWERDOWN) { + unlock_fb_info(info); + console_unlock(); + return -EINVAL; + } ret = fb_blank(info, arg); /* might again call into fb_blank */ fbcon_fb_blanked(info, arg);