From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753328AbeDCVMe (ORCPT ); Tue, 3 Apr 2018 17:12:34 -0400 Received: from gateway22.websitewelcome.com ([192.185.47.163]:25006 "EHLO gateway22.websitewelcome.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753156AbeDCVMd (ORCPT ); Tue, 3 Apr 2018 17:12:33 -0400 Date: Tue, 3 Apr 2018 16:12:32 -0500 From: "Gustavo A. R. Silva" To: Zhichang Yuan Cc: linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" Subject: [PATCH] lib: logic_pio: Fix potential NULL pointer dereference Message-ID: <20180403211232.GA29526@embeddedor.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.24 (2015-08-30) X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - gator4166.hostgator.com X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - embeddedor.com X-BWhitelist: no X-Source-IP: 189.145.54.187 X-Source-L: No X-Exim-ID: 1f3TEH-000TEW-1u X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: (embeddedor) [189.145.54.187]:53738 X-Source-Auth: gustavo@embeddedor.com X-Email-Count: 13 X-Source-Cap: Z3V6aWRpbmU7Z3V6aWRpbmU7Z2F0b3I0MTY2Lmhvc3RnYXRvci5jb20= X-Local-Domain: yes Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org new_range is being dereferenced before it is null checked, hence there is a potential null pointer dereference. Fix this by moving the pointer dereference after new_range has been properly null checked. Addresses-Coverity-ID: 1466163 ("Dereference before null check") Fixes: 0a7198426259 ("lib: Add generic PIO mapping method") Signed-off-by: Gustavo A. R. Silva --- lib/logic_pio.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/lib/logic_pio.c b/lib/logic_pio.c index 29cedea..30dfdce 100644 --- a/lib/logic_pio.c +++ b/lib/logic_pio.c @@ -33,8 +33,8 @@ static DEFINE_MUTEX(io_range_mutex); int logic_pio_register_range(struct logic_pio_hwaddr *new_range) { struct logic_pio_hwaddr *range; - resource_size_t start = new_range->hw_start; - resource_size_t end = new_range->hw_start + new_range->size; + resource_size_t start; + resource_size_t end; resource_size_t mmio_sz = 0; resource_size_t iio_sz = MMIO_UPPER_LIMIT; int ret = 0; @@ -42,6 +42,9 @@ int logic_pio_register_range(struct logic_pio_hwaddr *new_range) if (!new_range || !new_range->fwnode || !new_range->size) return -EINVAL; + start = new_range->hw_start; + end = new_range->hw_start + new_range->size; + mutex_lock(&io_range_mutex); list_for_each_entry_rcu(range, &io_range_list, list) { if (range->fwnode == new_range->fwnode) { -- 2.7.4