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,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 CA32CC4361A for ; Wed, 12 May 2021 18:45:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AFF766142F for ; Wed, 12 May 2021 18:45:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1358384AbhELSoE (ORCPT ); Wed, 12 May 2021 14:44:04 -0400 Received: from mail.kernel.org ([198.145.29.99]:35836 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243588AbhELQlg (ORCPT ); Wed, 12 May 2021 12:41:36 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 58DEA61CE6; Wed, 12 May 2021 16:05:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1620835515; bh=Uxz7oMteSxfFHU48bBX/AmUX+Xv2sHNP8sQl4iLm4c0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=J3utnVfNFWUlOwMWotJvkuG7BUD4N5rxFU+8i1cAl7G8xzaqgsJMGqQLZdkL+bPIJ 9Mup6VLRqBGW7AL74Qw42n24XVm9G+SlyAfsYSyKzltsjRidSmocv2pUP9K6ifYaYx XL42WVtVaAFadNvmmdtmDuukpuQwsihv83Jj6NUc= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dan Carpenter , Joel Stanley , Patrick Venture , Arnd Bergmann , Sasha Levin Subject: [PATCH 5.12 340/677] soc: aspeed: fix a ternary sign expansion bug Date: Wed, 12 May 2021 16:46:26 +0200 Message-Id: <20210512144848.580662928@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210512144837.204217980@linuxfoundation.org> References: <20210512144837.204217980@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: Dan Carpenter [ Upstream commit 5ffa828534036348fa90fb3079ccc0972d202c4a ] The intent here was to return negative error codes but it actually returns positive values. The problem is that type promotion with ternary operations is quite complicated. "ret" is an int. "copied" is a u32. And the snoop_file_read() function returns long. What happens is that "ret" is cast to u32 and becomes positive then it's cast to long and it's still positive. Fix this by removing the ternary so that "ret" is type promoted directly to long. Fixes: 3772e5da4454 ("drivers/misc: Aspeed LPC snoop output using misc chardev") Signed-off-by: Dan Carpenter Signed-off-by: Joel Stanley Reviewed-by: Patrick Venture Link: https://lore.kernel.org/r/YIE90PSXsMTa2Y8n@mwanda Link: https://lore.kernel.org/r/20210423000919.1249474-1-joel@jms.id.au' Signed-off-by: Arnd Bergmann Signed-off-by: Sasha Levin --- drivers/soc/aspeed/aspeed-lpc-snoop.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/soc/aspeed/aspeed-lpc-snoop.c b/drivers/soc/aspeed/aspeed-lpc-snoop.c index 20acac6342ef..5828f94b8a7d 100644 --- a/drivers/soc/aspeed/aspeed-lpc-snoop.c +++ b/drivers/soc/aspeed/aspeed-lpc-snoop.c @@ -95,8 +95,10 @@ static ssize_t snoop_file_read(struct file *file, char __user *buffer, return -EINTR; } ret = kfifo_to_user(&chan->fifo, buffer, count, &copied); + if (ret) + return ret; - return ret ? ret : copied; + return copied; } static __poll_t snoop_file_poll(struct file *file, -- 2.30.2