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=-19.7 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 CEF6EC43460 for ; Wed, 5 May 2021 17:01:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 97D3B61059 for ; Wed, 5 May 2021 17:01:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235717AbhEERCT (ORCPT ); Wed, 5 May 2021 13:02:19 -0400 Received: from mail.kernel.org ([198.145.29.99]:46196 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235891AbhEEQ4C (ORCPT ); Wed, 5 May 2021 12:56:02 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 0281261998; Wed, 5 May 2021 16:39:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1620232745; bh=7VE5b9CxV3ASOEntwtlfqPzYNsu2TDCZyjS7kRMqH48=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=GT7kINwfBLduYtXQbF0LlL4Pw1FwiWsiemaDX5tgkKvGd4fnyYc7vnVhX/Ayw7bmA xONU6Pik0UO/Icnxu011r47hXRPwbqR2OMJyD2/HPUOlypsARWfd0hSndi8EWIniRx pH6pUJiJ1zeJzLCflC2B8cYCdBoK1r/39fRg8128LOH22eNMN6BO09FX9u8MDjMA2w KCZfsc2839bPxJpSO+C85G01V8HHpl5KnOmfR38HOeRkw+IH6aj5GA7bKLl3n1xllu wKk64/MWCoAGPcbWC0PgSRoam4duW3z0iScxd7LNSzkbbGu4bHiS3owMDJumib1BPj nDYGxxZ+fnntQ== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Wolfram Sang , syzbot+ffb0b3ffa6cfbc7d7b3f@syzkaller.appspotmail.com, Wolfram Sang , Sasha Levin , linux-i2c@vger.kernel.org Subject: [PATCH AUTOSEL 5.4 06/46] i2c: bail out early when RDWR parameters are wrong Date: Wed, 5 May 2021 12:38:16 -0400 Message-Id: <20210505163856.3463279-6-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210505163856.3463279-1-sashal@kernel.org> References: <20210505163856.3463279-1-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-i2c@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 94beacc41302..a3fec3df11b6 100644 --- a/drivers/i2c/i2c-dev.c +++ b/drivers/i2c/i2c-dev.c @@ -440,8 +440,13 @@ 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; -- 2.30.2