From patchwork Wed Feb 2 23:16:33 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yizhuo Zhai X-Patchwork-Id: 12733531 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 879F2C433F5 for ; Wed, 2 Feb 2022 23:17:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241401AbiBBXRj (ORCPT ); Wed, 2 Feb 2022 18:17:39 -0500 Received: from mx6.ucr.edu ([138.23.62.71]:6602 "EHLO mx6.ucr.edu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239155AbiBBXRi (ORCPT ); Wed, 2 Feb 2022 18:17:38 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=ucr.edu; i=@ucr.edu; q=dns/txt; s=selector3; t=1643843859; x=1675379859; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=XA4HzDe0AEvwI/VRCaorqRe1KBJyowOMBeCxGfa6hn4=; b=f4MeDW74oZ6Q8N7EvkPDbrSy5san7ca2jSeiGmwiDhY0s+4fAqEyxXKo ceA6Q6EJKCWGbRALZlmvDuQA6gCCqFRdIuIQ7+hGmZKSwfoCXTK+caXcV MjDuKhH01Iskg82Lt9v3JdjKfQWMriQtQOsQ4cUoP2FvvS2qRKSzYvvuK 3SPCt5sIMAmkMZJ1jN4MiflXl//plyVP5FjZlz7B3xisB8vAkJJuFWLLx NWnrGstiCw+EhU5EMpLfRnmjYp547KGNTuJ4AfbM6dfq3FMG8bDSXotB/ Y7WGbaWra9fLOlbC06PRGe7APRcxRCNtaZR6yICdA/yxDXpAEElqghsgk w==; X-IronPort-AV: E=Sophos;i="5.88,338,1635231600"; d="scan'208";a="278234505" Received: from mail-pj1-f71.google.com ([209.85.216.71]) by smtpmx6.ucr.edu with ESMTP/TLS/ECDHE-RSA-AES128-GCM-SHA256; 02 Feb 2022 15:17:27 -0800 Received: by mail-pj1-f71.google.com with SMTP id js6-20020a17090b148600b001b835ae2017so1560758pjb.5 for ; Wed, 02 Feb 2022 15:17:27 -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=x0gpjDLXaul+KimMP/te05qJYZBYJvmQ+lbw67iuhZI=; b=iG0hqIojQ+Btn3YyfJz0zIh+ids2UdHlcdajOgKekWODbOVBE25xUjQthNVNVCYJZL ziLiUrKHuhoXAKfwZ6C7H0nGSqSQhiN5jcNjOymYda/yMkGSCQpR8Jg0jBCRvZRWu7Ly FY1UCAwviBYMivvY4GLNBbBng5j7VlxTHZzhM= 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=x0gpjDLXaul+KimMP/te05qJYZBYJvmQ+lbw67iuhZI=; b=SAdZObgqH0yzh+t/HyZZ1hfN79ufU+GzyW1Ki7X3IF7RppyZ5jRgni43eSyuqAjHH5 368fb2icua5DA2q93lAqCFnVM8Ie+1jn/CSrKBa9v2QN8lLBeV6rlE3mJs6QTdm0yqOZ wiD+LjKkvBkYbfwuhAKVtLuGM+I3RzBJf0xN6iQ71a4elbq2BFdXGWTaNhkw3Zq2+tb8 +Yaitx2dxOLPL9Gnmg3DYxEsUv4NeLEdE2uKrvo3ibFuDXDZvmFbFl5AxiPQK6VHSGAW 417rW3CB6eP+DWVl/jJR0TORPI8Fx1WmXE3rrzidf7lgW5oG/kPS7MCbfC/llvjy5kk+ bZew== X-Gm-Message-State: AOAM531qxvBq2kO0pgSF4sy2h47cnTvswXojAa2gJFA4Q/x/dKkl0sEf KD4NNSzD/kI9v967LqJ4P4CrPFhsz/oas660tPKPxiO/BDenvHOrhFwJZRxw+9VM4fI2IkULhRk 8GSOxXHILYl4bSMdztjm7rLZR X-Received: by 2002:a05:6a00:114e:: with SMTP id b14mr32122976pfm.31.1643843838878; Wed, 02 Feb 2022 15:17:18 -0800 (PST) X-Google-Smtp-Source: ABdhPJwOOE+HHe74jnu6gkVO3QanT2cNSA16ZEnCIFi4F5dLBKqCPSoK9K2Dq+OswSZYFwgxrT9+zw== X-Received: by 2002:a05:6a00:114e:: with SMTP id b14mr32122959pfm.31.1643843838640; Wed, 02 Feb 2022 15:17:18 -0800 (PST) Received: from kq.cs.ucr.edu (kq.cs.ucr.edu. [169.235.27.223]) by smtp.googlemail.com with ESMTPSA id j14sm27383525pfj.218.2022.02.02.15.17.17 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 02 Feb 2022 15:17:18 -0800 (PST) From: Yizhuo Zhai Cc: Yizhuo Zhai , Helge Deller , Daniel Vetter , Matthew Wilcox , Sam Ravnborg , Xin Tan , Guenter Roeck , Zheyu Ma , Alex Deucher , Zhen Lei , Tetsuo Handa , Xiyu Yang , linux-fbdev@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Subject: [PATCH v4] fbdev: fbmem: Fix the implicit type casting Date: Wed, 2 Feb 2022 15:16:33 -0800 Message-Id: <20220202231636.1433050-1-yzhai003@ucr.edu> X-Mailer: git-send-email 2.25.1 In-Reply-To: <882bfe4e-a5b6-2b2c-167b-eda8c08419e3@gmx.de> References: <882bfe4e-a5b6-2b2c-167b-eda8c08419e3@gmx.de> 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 | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/video/fbdev/core/fbmem.c b/drivers/video/fbdev/core/fbmem.c index 0fa7ede94fa6..b3352e23caaa 100644 --- a/drivers/video/fbdev/core/fbmem.c +++ b/drivers/video/fbdev/core/fbmem.c @@ -1162,6 +1162,8 @@ 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) + return -EINVAL; ret = fb_blank(info, arg); /* might again call into fb_blank */ fbcon_fb_blanked(info, arg);