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=unavailable 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 6F15CC4332F for ; Thu, 9 Sep 2021 13:00:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 57ABD60ED8 for ; Thu, 9 Sep 2021 13:00:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1353696AbhIINBZ (ORCPT ); Thu, 9 Sep 2021 09:01:25 -0400 Received: from mail.kernel.org ([198.145.29.99]:59102 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1355115AbhIIMxq (ORCPT ); Thu, 9 Sep 2021 08:53:46 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 470E96324A; Thu, 9 Sep 2021 11:57:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1631188673; bh=AybPZpErDiE8fAce0XBaZMb0g2M5ehifYSknZWnrXm0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=sSnHRBOifpAybUgZGZ0oKiUSD3H0IoGedu1qQELpNma32dchNYHKAnHFNkeoE/jGW FIyiun1H0zkbqVpClCLoJqewbpsWZtIstJjpUP/k5VSijpc1cB2whar/DUVVxucSwx FldwiPppq4uwsE5kGUGD9hfC1A9I4AUFS1Xybjzn7eKFFZMNKqSL5Z7eIN15qtZfOg dAQjRHP2k6Jqz1f1qWejIBWal4IijMhl+P/d5H4FLFMePNUkOg4Ht66IvIp3wkqHHl FDbCz/NONcNnoAYwg+4EnxssYYI47TnpTDjxJO9pE1DBEFl3en3vFvIZxLuk8TLolj YivKgssoozrnQ== 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 4.19 21/74] video: fbdev: riva: Error out if 'pixclock' equals zero Date: Thu, 9 Sep 2021 07:56:33 -0400 Message-Id: <20210909115726.149004-21-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210909115726.149004-1-sashal@kernel.org> References: <20210909115726.149004-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-fbdev@vger.kernel.org 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 cc242ba057d3..dfa81b641f9f 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