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 C6035C433EF for ; Thu, 9 Sep 2021 13:35:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B1E6060F6C for ; Thu, 9 Sep 2021 13:35:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1376403AbhIINeW (ORCPT ); Thu, 9 Sep 2021 09:34:22 -0400 Received: from mail.kernel.org ([198.145.29.99]:53482 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1358418AbhIINHT (ORCPT ); Thu, 9 Sep 2021 09:07:19 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id D31A2632B2; Thu, 9 Sep 2021 12:00:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1631188837; bh=fszcVQ54+MRHL1zDTWIOZl6b4IzBfRpD5N0vgFm23/Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Oe5kbj9FvMIzPKsqBOJnkeDqMccHTV4nJ1Woo0F+QU943yN5PtuSlarZGSSQ9cZpa LdGM6QJQBj+UpL6ZJ/wktpMSgrWkAzwHZnjzUel9XmdtJoDZCSC5LVqqQ3rK7beHrK AjKmzR+u/d+VgYGBIjfjcapGJqy8ze2ClF+LxjFuL/UleIVcycoOHz1QLfU4yrPF+E 0yaXaVSkB/sjgryCNiy0DbLn1WVfnLx4z9LthDOEabIgWoUpKfrnkEZJGmK5/JlZer QnLd1Hcxd7ROpF+uzO/rGbkl025GMW2wTZ0PBj8C55iGj+Z2wEw7+SjIuVl6lmMNdn jHJ835/xYlEAw== 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 4.9 17/48] video: fbdev: riva: Error out if 'pixclock' equals zero Date: Thu, 9 Sep 2021 07:59:44 -0400 Message-Id: <20210909120015.150411-17-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210909120015.150411-1-sashal@kernel.org> References: <20210909120015.150411-1-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-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 2ef26ad99341..69f3acd405c5 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