From patchwork Thu May 20 09:21:15 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 444420 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=-19.1 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=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 D0195C4360C for ; Thu, 20 May 2021 10:04:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B765C61D1A for ; Thu, 20 May 2021 10:04:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235166AbhETKF7 (ORCPT ); Thu, 20 May 2021 06:05:59 -0400 Received: from mail.kernel.org ([198.145.29.99]:37258 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235001AbhETKD5 (ORCPT ); Thu, 20 May 2021 06:03:57 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 34B0C61923; Thu, 20 May 2021 09:40:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1621503623; bh=khiZR3WpiPPiv2JrwnDHVhgiP3lU5CeCHaaScLhI3x0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=aPrA88dXa3T+8/ot+NeaDPU8OlKWPI4qiqUZlmC9smspUkhIq4HSgK8kp8X1+rgDw GS5zG0wGHCb3WNtjhA6dpv/a4EKBr4cCrH4nCSqLaDtJbafRO/EZHy8cTj7/XPoVOn M0hdUzVVn4GIJxe+dWdEmT7DxgHUkp/MK9H9hMDk= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot+ffb0b3ffa6cfbc7d7b3f@syzkaller.appspotmail.com, Wolfram Sang , Wolfram Sang , Sasha Levin Subject: [PATCH 4.19 306/425] i2c: bail out early when RDWR parameters are wrong Date: Thu, 20 May 2021 11:21:15 +0200 Message-Id: <20210520092141.494231511@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210520092131.308959589@linuxfoundation.org> References: <20210520092131.308959589@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Wolfram Sang [ Upstream commit 71581562ee36032d2d574a9b23ad4af6d6a64cf7 ] The buggy parameters currently get caught later, but emit a noisy WARN. Userspace should not be able to trigger this, so add similar checks much earlier. Also avoids some unneeded code paths, of course. Apply kernel coding stlye to a comment while here. Reported-by: syzbot+ffb0b3ffa6cfbc7d7b3f@syzkaller.appspotmail.com Tested-by: syzbot+ffb0b3ffa6cfbc7d7b3f@syzkaller.appspotmail.com Signed-off-by: Wolfram Sang Signed-off-by: Wolfram Sang Signed-off-by: Sasha Levin --- drivers/i2c/i2c-dev.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/i2c/i2c-dev.c b/drivers/i2c/i2c-dev.c index cbda91a0cb5f..1d10ee86299d 100644 --- a/drivers/i2c/i2c-dev.c +++ b/drivers/i2c/i2c-dev.c @@ -448,8 +448,13 @@ static long i2cdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg) sizeof(rdwr_arg))) return -EFAULT; - /* Put an arbitrary limit on the number of messages that can - * be sent at once */ + if (!rdwr_arg.msgs || rdwr_arg.nmsgs == 0) + return -EINVAL; + + /* + * Put an arbitrary limit on the number of messages that can + * be sent at once + */ if (rdwr_arg.nmsgs > I2C_RDWR_IOCTL_MAX_MSGS) return -EINVAL;