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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 4B057C4828F for ; Fri, 2 Feb 2024 18:40:29 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 5C33E10E783; Fri, 2 Feb 2024 18:40:28 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.b="bbS/7aXh"; dkim-atps=neutral Received: from sin.source.kernel.org (sin.source.kernel.org [145.40.73.55]) by gabe.freedesktop.org (Postfix) with ESMTPS id 8EDA010E60F for ; Fri, 2 Feb 2024 18:40:26 +0000 (UTC) Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sin.source.kernel.org (Postfix) with ESMTP id D6A95CE2C61; Fri, 2 Feb 2024 18:40:24 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id EB75EC433C7; Fri, 2 Feb 2024 18:40:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1706899224; bh=OQN9U8WPS8z0nO6aDPPSkvoCxJT81vr63obFC3R8S94=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=bbS/7aXhoLSD59TtTnZsnQhEP3XejFkpDERE1gg+XNA8FXyj4BdkLWBOo6CUEc8Hb t3nO8tCkLe+F0cKN5PCxVsGPSoMMYnh2+ylxTlLtVu88aouMe7Zj4FDseWs4MIWfqn JlBRJYnlLLwfsFKjBoO08Xh7ZazC8srjEPzXw6x+Cm6oyIuIqeHVBCneN6B/of4a1f ww36zViXeKzzyEf44MlRH49w4e7GxEuPX/npyMwoIFRUw34e6Lmj/l4mkPu5NWpykT OgXbmXPaFz/64BVZ8zA2LWgRT9uLU8I9tovbAK7T+GcZBRCK5lxnw8s9pseistjdAm wgW4ZizkeyEdQ== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Fullway Wang , Helge Deller , Sasha Levin , tzimmermann@suse.de, sam@ravnborg.org, javierm@redhat.com, linux-fbdev@vger.kernel.org, dri-devel@lists.freedesktop.org Subject: [PATCH AUTOSEL 6.6 04/21] fbdev: sis: Error out if pixclock equals zero Date: Fri, 2 Feb 2024 13:39:51 -0500 Message-ID: <20240202184015.540966-4-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240202184015.540966-1-sashal@kernel.org> References: <20240202184015.540966-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.6.15 Content-Transfer-Encoding: 8bit X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" From: Fullway Wang [ Upstream commit e421946be7d9bf545147bea8419ef8239cb7ca52 ] The userspace program could pass any values to the driver through ioctl() interface. If the driver doesn't check the value of pixclock, it may cause divide-by-zero error. In sisfb_check_var(), var->pixclock is used as a divisor to caculate drate before it is checked against zero. Fix this by checking it at the beginning. This is similar to CVE-2022-3061 in i740fb which was fixed by commit 15cf0b8. Signed-off-by: Fullway Wang Signed-off-by: Helge Deller Signed-off-by: Sasha Levin --- drivers/video/fbdev/sis/sis_main.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/video/fbdev/sis/sis_main.c b/drivers/video/fbdev/sis/sis_main.c index 0f5374f6ef05..6d524a65af18 100644 --- a/drivers/video/fbdev/sis/sis_main.c +++ b/drivers/video/fbdev/sis/sis_main.c @@ -1475,6 +1475,8 @@ sisfb_check_var(struct fb_var_screeninfo *var, struct fb_info *info) vtotal = var->upper_margin + var->lower_margin + var->vsync_len; + if (!var->pixclock) + return -EINVAL; pixclock = var->pixclock; if((var->vmode & FB_VMODE_MASK) == FB_VMODE_NONINTERLACED) { -- 2.43.0