From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:42432 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932645AbeCWKKN (ORCPT ); Fri, 23 Mar 2018 06:10:13 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Michael Mera , Kalle Valo , Sasha Levin Subject: [PATCH 4.9 131/177] ath10k: fix out of bounds access to local buffer Date: Fri, 23 Mar 2018 10:54:19 +0100 Message-Id: <20180323094211.007752670@linuxfoundation.org> In-Reply-To: <20180323094205.090519271@linuxfoundation.org> References: <20180323094205.090519271@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Michael Mera [ Upstream commit a16703aaeaedec7a8bee5be5522c7c3e75478951 ] During write to debugfs file simulate_fw_crash, fixed-size local buffer 'buf' is accessed and modified at index 'count-1', where 'count' is the size of the write (so potentially out of bounds). This patch fixes this problem. Signed-off-by: Michael Mera Signed-off-by: Kalle Valo Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/net/wireless/ath/ath10k/debug.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) --- a/drivers/net/wireless/ath/ath10k/debug.c +++ b/drivers/net/wireless/ath/ath10k/debug.c @@ -624,17 +624,21 @@ static ssize_t ath10k_write_simulate_fw_ size_t count, loff_t *ppos) { struct ath10k *ar = file->private_data; - char buf[32]; + char buf[32] = {0}; + ssize_t rc; int ret; - simple_write_to_buffer(buf, sizeof(buf) - 1, ppos, user_buf, count); + /* filter partial writes and invalid commands */ + if (*ppos != 0 || count >= sizeof(buf) || count == 0) + return -EINVAL; - /* make sure that buf is null terminated */ - buf[sizeof(buf) - 1] = 0; + rc = simple_write_to_buffer(buf, sizeof(buf) - 1, ppos, user_buf, count); + if (rc < 0) + return rc; /* drop the possible '\n' from the end */ - if (buf[count - 1] == '\n') - buf[count - 1] = 0; + if (buf[*ppos - 1] == '\n') + buf[*ppos - 1] = '\0'; mutex_lock(&ar->conf_mutex);