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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,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 D2206C4332F for ; Sun, 8 Sep 2019 12:59:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A349620693 for ; Sun, 8 Sep 2019 12:59:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1567947565; bh=0OjlmtzajQP3fonjsDscpmVG6sUf8ItzbOVzKh6nRrA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=ze8P/e4HnNL+DouCPI4fQsNhWipSJIjz/lHgwMRDqNCo74pYEs/H2srnYhmd07niH xM82yuVGWLet88m1xJ/jvU+unMJzvd6YsCSfT3lL/CI7Rx9FP908kc5KLqjrply0y1 K5b84/VsQUK5U1mQBrtw+n09xUuPvgp3K6sF6XNU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726534AbfIHM7Y (ORCPT ); Sun, 8 Sep 2019 08:59:24 -0400 Received: from mail.kernel.org ([198.145.29.99]:33382 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730268AbfIHMqB (ORCPT ); Sun, 8 Sep 2019 08:46:01 -0400 Received: from localhost (unknown [62.28.240.114]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id A1B38218AC; Sun, 8 Sep 2019 12:46:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1567946761; bh=0OjlmtzajQP3fonjsDscpmVG6sUf8ItzbOVzKh6nRrA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ZfCgzEvAd3ZvLGcqyNgebzjAwRcyndpwbrD3SYz+MTGRVLPv6OFGxFHTh0p91Ll/9 LVYq4NEk6UMUwIFZZ5OkbSYv8RGC2cZ0dlMhrguIuonn7h6vZicTeRAuoTJDZkcwxd CATRwYIB46TfXer5iL+lsXO2fERRvQhOgXHG3OZI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Hubert Denkmair , Martin Sperl , Stefan Wahren , Mark Brown , Sasha Levin Subject: [PATCH 4.14 30/40] spi: bcm2835aux: remove dangerous uncontrolled read of fifo Date: Sun, 8 Sep 2019 13:42:03 +0100 Message-Id: <20190908121128.360829184@linuxfoundation.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20190908121114.260662089@linuxfoundation.org> References: <20190908121114.260662089@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org [ Upstream commit c7de8500fd8ecbb544846dd5f11dca578c3777e1 ] This read of the fifo is a potential candidate for a race condition as the spi transfer is not necessarily finished and so can lead to an early read of the fifo that still misses data. So it has been removed. Fixes: 1ea29b39f4c812ec ("spi: bcm2835aux: add bcm2835 auxiliary spi device...") Suggested-by: Hubert Denkmair Signed-off-by: Martin Sperl Acked-by: Stefan Wahren Signed-off-by: Mark Brown Signed-off-by: Sasha Levin --- drivers/spi/spi-bcm2835aux.c | 7 ------- 1 file changed, 7 deletions(-) diff --git a/drivers/spi/spi-bcm2835aux.c b/drivers/spi/spi-bcm2835aux.c index 97cb3beb9cc62..4454d9c6a3dd4 100644 --- a/drivers/spi/spi-bcm2835aux.c +++ b/drivers/spi/spi-bcm2835aux.c @@ -194,13 +194,6 @@ static void bcm2835aux_spi_transfer_helper(struct bcm2835aux_spi *bs) BCM2835_AUX_SPI_STAT_TX_FULL))) { bcm2835aux_wr_fifo(bs); } - - /* and check if we have reached "done" */ - while (bs->rx_len && - (!(bcm2835aux_rd(bs, BCM2835_AUX_SPI_STAT) & - BCM2835_AUX_SPI_STAT_BUSY))) { - bcm2835aux_rd_fifo(bs); - } } static irqreturn_t bcm2835aux_spi_interrupt(int irq, void *dev_id) -- 2.20.1