Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754087AbdFEQbQ (ORCPT ); Mon, 5 Jun 2017 12:31:16 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:60518 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751937AbdFEQbN (ORCPT ); Mon, 5 Jun 2017 12:31:13 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Anush Seetharaman , Dan Williams , "Rafael J. Wysocki" Subject: [PATCH 4.11 056/115] ACPI / sysfs: fix acpi_get_table() leak / acpi-sysfs denial of service Date: Mon, 5 Jun 2017 18:17:29 +0200 Message-Id: <20170605153059.448044262@linuxfoundation.org> X-Mailer: git-send-email 2.13.0 In-Reply-To: <20170605153056.650217313@linuxfoundation.org> References: <20170605153056.650217313@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1714 Lines: 51 4.11-stable review patch. If anyone has any objections, please let me know. ------------------ From: Dan Williams commit 0de0e198bc7191a0e46cf71f66fec4d07ca91396 upstream. Reading an ACPI table through the /sys/firmware/acpi/tables interface more than 65,536 times leads to the following log message: ACPI Error: Table ffff88033595eaa8, Validation count is zero after increment (20170119/tbutils-423) ...and the table being unavailable until the next reboot. Add the missing acpi_put_table() so the table ->validation_count is decremented after each read. Reported-by: Anush Seetharaman Fixes: 174cc7187e6f "ACPICA: Tables: Back port acpi_get_table_with_size() ..." Signed-off-by: Dan Williams Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman --- drivers/acpi/sysfs.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) --- a/drivers/acpi/sysfs.c +++ b/drivers/acpi/sysfs.c @@ -333,14 +333,17 @@ static ssize_t acpi_table_show(struct fi container_of(bin_attr, struct acpi_table_attr, attr); struct acpi_table_header *table_header = NULL; acpi_status status; + ssize_t rc; status = acpi_get_table(table_attr->name, table_attr->instance, &table_header); if (ACPI_FAILURE(status)) return -ENODEV; - return memory_read_from_buffer(buf, count, &offset, - table_header, table_header->length); + rc = memory_read_from_buffer(buf, count, &offset, table_header, + table_header->length); + acpi_put_table(table_header); + return rc; } static int acpi_table_attr_init(struct kobject *tables_obj,