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=-20.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, 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 6C414C433FE for ; Mon, 20 Sep 2021 18:17:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 592FC61A0B for ; Mon, 20 Sep 2021 18:17:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1377441AbhITSS5 (ORCPT ); Mon, 20 Sep 2021 14:18:57 -0400 Received: from mail.kernel.org ([198.145.29.99]:33268 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1358727AbhITSHh (ORCPT ); Mon, 20 Sep 2021 14:07:37 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 455AE61A3C; Mon, 20 Sep 2021 17:18:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1632158314; bh=lLd16bR7KFDAcQyJi/kQnKCTrzwAXDW4mmvfvqiwpbg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=UEfm04KGalgUK0dnI0t8gUh8SuKCwWiSWNmSDNZ3n01SWF8xy3k4HjEP67+JmzB3W yEKENVoEJ5rouHZ8fzDQEvUVLzhzTBhp+LEgPZ7/dVnzEC1oQrafXjOs38tligC16s 8DMcJ35ww9id2GMv67iywLJzBZsodmXTFp2IRbNE= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Zheyu Ma , Sam Ravnborg , Sasha Levin Subject: [PATCH 5.4 100/260] video: fbdev: riva: Error out if pixclock equals zero Date: Mon, 20 Sep 2021 18:41:58 +0200 Message-Id: <20210920163934.532567660@linuxfoundation.org> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20210920163931.123590023@linuxfoundation.org> References: <20210920163931.123590023@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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 ca593a3e41d7..51c9d9508c0b 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