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 X-Spam-Level: X-Spam-Status: No, score=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DA5D9C43217 for ; Thu, 9 Sep 2021 12:01:39 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id A820C6108B for ; Thu, 9 Sep 2021 12:01:39 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org A820C6108B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id C50286E855; Thu, 9 Sep 2021 12:01:38 +0000 (UTC) Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by gabe.freedesktop.org (Postfix) with ESMTPS id D80B56E855 for ; Thu, 9 Sep 2021 12:01:34 +0000 (UTC) Received: by mail.kernel.org (Postfix) with ESMTPSA id EBAD460F4A; Thu, 9 Sep 2021 12:01:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1631188894; bh=P2dWfA3+6h1FBHe0VI/ugsM4VtXffXqmR7Mk0eeENhk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Jysc4NaCRM7uabsEsZ7vsymbZDN/kVETtt0UCYB27o1vsR6K1aEnS5XvXHgahePuQ HeFu1ol5G6LROJByB0i8dVFIZaAxgA+6ZETZvpvLpk2O9sRaKIwbuKCAZCBkbBg3Yk nvX3DIQVs2SbGtuZv7yl9FULUZ8pYAHdG3TTy/dC73zNNICbTpxZyiPbfRjR6xSCTl X2Y/ZuHwfGYO8SBCw6wU8ghTi4wFlHRfx/7NGlxWDoZYInDIr5lAIy0yy1wE0O3t/b Zo+51BT27vmtx6Em6YFbgNh0Tuz4P0g+syxipI825TzA6q/6Fsblr7H7Q5teZj0pTK fIZGuqAbSXNIQ== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Zheyu Ma , Sam Ravnborg , Sasha Levin , linux-fbdev@vger.kernel.org, dri-devel@lists.freedesktop.org Subject: [PATCH AUTOSEL 4.4 14/35] video: fbdev: riva: Error out if 'pixclock' equals zero Date: Thu, 9 Sep 2021 08:00:55 -0400 Message-Id: <20210909120116.150912-14-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210909120116.150912-1-sashal@kernel.org> References: <20210909120116.150912-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore 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: Zheyu Ma [ Upstream commit f92763cb0feba247e0939ed137b495601fd072a5 ] 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 error. Fix this by checking whether 'pixclock' is zero first. The following log reveals it: [ 33.396850] divide error: 0000 [#1] PREEMPT SMP KASAN PTI [ 33.396864] CPU: 5 PID: 11754 Comm: i740 Not tainted 5.14.0-rc2-00513-gac532c9bbcfb-dirty #222 [ 33.396883] RIP: 0010:riva_load_video_mode+0x417/0xf70 [ 33.396969] Call Trace: [ 33.396973] ? debug_smp_processor_id+0x1c/0x20 [ 33.396984] ? tick_nohz_tick_stopped+0x1a/0x90 [ 33.396996] ? rivafb_copyarea+0x3c0/0x3c0 [ 33.397003] ? wake_up_klogd.part.0+0x99/0xd0 [ 33.397014] ? vprintk_emit+0x110/0x4b0 [ 33.397024] ? vprintk_default+0x26/0x30 [ 33.397033] ? vprintk+0x9c/0x1f0 [ 33.397041] ? printk+0xba/0xed [ 33.397054] ? record_print_text.cold+0x16/0x16 [ 33.397063] ? __kasan_check_read+0x11/0x20 [ 33.397074] ? profile_tick+0xc0/0x100 [ 33.397084] ? __sanitizer_cov_trace_const_cmp4+0x24/0x80 [ 33.397094] ? riva_set_rop_solid+0x2a0/0x2a0 [ 33.397102] rivafb_set_par+0xbe/0x610 [ 33.397111] ? riva_set_rop_solid+0x2a0/0x2a0 [ 33.397119] fb_set_var+0x5bf/0xeb0 [ 33.397127] ? fb_blank+0x1a0/0x1a0 [ 33.397134] ? lock_acquire+0x1ef/0x530 [ 33.397143] ? lock_release+0x810/0x810 [ 33.397151] ? lock_is_held_type+0x100/0x140 [ 33.397159] ? ___might_sleep+0x1ee/0x2d0 [ 33.397170] ? __mutex_lock+0x620/0x1190 [ 33.397180] ? trace_hardirqs_on+0x6a/0x1c0 [ 33.397190] do_fb_ioctl+0x31e/0x700 Signed-off-by: Zheyu Ma Signed-off-by: Sam Ravnborg Link: https://patchwork.freedesktop.org/patch/msgid/1627293835-17441-4-git-send-email-zheyuma97@gmail.com Signed-off-by: Sasha Levin --- drivers/video/fbdev/riva/fbdev.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/video/fbdev/riva/fbdev.c b/drivers/video/fbdev/riva/fbdev.c index f1ad2747064b..6e5e29fe13db 100644 --- a/drivers/video/fbdev/riva/fbdev.c +++ b/drivers/video/fbdev/riva/fbdev.c @@ -1088,6 +1088,9 @@ static int rivafb_check_var(struct fb_var_screeninfo *var, struct fb_info *info) int mode_valid = 0; NVTRACE_ENTER(); + if (!var->pixclock) + return -EINVAL; + switch (var->bits_per_pixel) { case 1 ... 8: var->red.offset = var->green.offset = var->blue.offset = 0; -- 2.30.2