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 BD37BC4332F for ; Thu, 9 Sep 2021 11:57:57 +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 90DA56324C for ; Thu, 9 Sep 2021 11:57:57 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 90DA56324C 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 72DAF6E839; Thu, 9 Sep 2021 11:57:55 +0000 (UTC) Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by gabe.freedesktop.org (Postfix) with ESMTPS id EDB696E835 for ; Thu, 9 Sep 2021 11:57:51 +0000 (UTC) Received: by mail.kernel.org (Postfix) with ESMTPSA id 0DBE16325E; Thu, 9 Sep 2021 11:57:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1631188671; bh=d7EUfqwWWpV7h3TBHRCTu2b8IRuzuCKWsO/Z6kfeEZ0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=RB0UpN1lsMZWrfrP7/jgU4VaBtOGgh2Ofs6alQtNFzPlvCApo1DGO+2iZR4Pfs88x vF4RCY/UNK/e6j+Z2WVu/pgMMn2bIrgb1XRT1pVDTC+jYM9MFKs13YGbeaaJsYqJa9 mJE35u8m/sDw9SY0mCV2EXN9rTQrfkkJoq2ed/wM0jH9BiZZWxJf4phJKpeM9Fiago GFnsYNUmisJ1W8psI0m9N2F1dqrH001n9iU5xCxRR+RoJes7sd/jwUcJGNVvEfc7w1 zIr/46u51tE1tr92nPpbHW5VQFeNcO8UyDx+FuAUgWob5KpyqMtUdqZ6IkAGN73jzk tO0tDMs5Wv+lA== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Zheyu Ma , Sam Ravnborg , Sasha Levin , dri-devel@lists.freedesktop.org, linux-fbdev@vger.kernel.org Subject: [PATCH AUTOSEL 4.19 20/74] video: fbdev: kyro: Error out if 'pixclock' equals zero Date: Thu, 9 Sep 2021 07:56:32 -0400 Message-Id: <20210909115726.149004-20-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 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 1520b4b7ba964f8eec2e7dd14c571d50de3e5191 ] 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 because the value of 'lineclock' and 'frameclock' will be zero. Fix this by checking whether 'pixclock' is zero in kyrofb_check_var(). The following log reveals it: [ 103.073930] divide error: 0000 [#1] PREEMPT SMP KASAN PTI [ 103.073942] CPU: 4 PID: 12483 Comm: syz-executor Not tainted 5.14.0-rc2-00478-g2734d6c1b1a0-dirty #118 [ 103.073959] RIP: 0010:kyrofb_set_par+0x316/0xc80 [ 103.074045] Call Trace: [ 103.074048] ? ___might_sleep+0x1ee/0x2d0 [ 103.074060] ? kyrofb_ioctl+0x330/0x330 [ 103.074069] fb_set_var+0x5bf/0xeb0 [ 103.074078] ? fb_blank+0x1a0/0x1a0 [ 103.074085] ? lock_acquire+0x3bd/0x530 [ 103.074094] ? lock_release+0x810/0x810 [ 103.074103] ? ___might_sleep+0x1ee/0x2d0 [ 103.074114] ? __mutex_lock+0x620/0x1190 [ 103.074126] ? trace_hardirqs_on+0x6a/0x1c0 [ 103.074137] do_fb_ioctl+0x31e/0x700 [ 103.074144] ? fb_getput_cmap+0x280/0x280 [ 103.074152] ? rcu_read_lock_sched_held+0x11/0x80 [ 103.074162] ? rcu_read_lock_sched_held+0x11/0x80 [ 103.074171] ? __sanitizer_cov_trace_switch+0x67/0xf0 [ 103.074181] ? __sanitizer_cov_trace_const_cmp2+0x20/0x80 [ 103.074191] ? do_vfs_ioctl+0x14b/0x16c0 [ 103.074199] ? vfs_fileattr_set+0xb60/0xb60 [ 103.074207] ? rcu_read_lock_sched_held+0x11/0x80 [ 103.074216] ? lock_release+0x483/0x810 [ 103.074224] ? __fget_files+0x217/0x3d0 [ 103.074234] ? __fget_files+0x239/0x3d0 [ 103.074243] ? do_fb_ioctl+0x700/0x700 [ 103.074250] fb_ioctl+0xe6/0x130 Signed-off-by: Zheyu Ma Signed-off-by: Sam Ravnborg Link: https://patchwork.freedesktop.org/patch/msgid/1627293835-17441-3-git-send-email-zheyuma97@gmail.com Signed-off-by: Sasha Levin --- drivers/video/fbdev/kyro/fbdev.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/video/fbdev/kyro/fbdev.c b/drivers/video/fbdev/kyro/fbdev.c index d7aa431e6846..74bf26b527b9 100644 --- a/drivers/video/fbdev/kyro/fbdev.c +++ b/drivers/video/fbdev/kyro/fbdev.c @@ -399,6 +399,9 @@ static int kyrofb_check_var(struct fb_var_screeninfo *var, struct fb_info *info) { struct kyrofb_info *par = info->par; + if (!var->pixclock) + return -EINVAL; + if (var->bits_per_pixel != 16 && var->bits_per_pixel != 32) { printk(KERN_WARNING "kyrofb: depth not supported: %u\n", var->bits_per_pixel); return -EINVAL; -- 2.30.2