From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752434AbdKVChI (ORCPT ); Tue, 21 Nov 2017 21:37:08 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:56730 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751841AbdKVCUX (ORCPT ); Tue, 21 Nov 2017 21:20:23 -0500 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Linus Torvalds" , "Leon Romanovsky" , "Arnd Bergmann" Date: Wed, 22 Nov 2017 01:58:13 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 117/133] IB/mlx4: fix sprintf format warning In-Reply-To: X-SA-Exim-Connect-IP: 2a02:8011:400e:2:6f00:88c8:c921:d332 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.51-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Arnd Bergmann commit d0dbf771309fecd73f4ac1566c1400cb12807ee2 upstream. gcc-7 points out that a negative port_num value would overflow the string buffer: drivers/infiniband/hw/mlx4/sysfs.c: In function 'mlx4_ib_device_register_sysfs': drivers/infiniband/hw/mlx4/sysfs.c:251:16: error: 'sprintf' may write a terminating nul past the end of the destination [-Werror=format-overflow=] drivers/infiniband/hw/mlx4/sysfs.c:251:2: note: 'sprintf' output between 2 and 11 bytes into a destination of size 10 drivers/infiniband/hw/mlx4/sysfs.c:303:17: error: 'sprintf' may write a terminating nul past the end of the destination [-Werror=format-overflow=] drivers/infiniband/hw/mlx4/sysfs.c:303:3: note: 'sprintf' output between 2 and 11 bytes into a destination of size 10 While we should be able to assume that port_num is positive here, making the buffer one byte longer has no downsides and avoids the warning. Fixes: c1e7e466120b ("IB/mlx4: Add iov directory in sysfs under the ib device") Link: http://lkml.kernel.org/r/20170714120720.906842-23-arnd@arndb.de Signed-off-by: Arnd Bergmann Reviewed-by: Leon Romanovsky Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Ben Hutchings --- drivers/infiniband/hw/mlx4/sysfs.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/infiniband/hw/mlx4/sysfs.c +++ b/drivers/infiniband/hw/mlx4/sysfs.c @@ -241,7 +241,7 @@ void del_sysfs_port_mcg_attr(struct mlx4 static int add_port_entries(struct mlx4_ib_dev *device, int port_num) { int i; - char buff[10]; + char buff[11]; struct mlx4_ib_iov_port *port = NULL; int ret = 0 ; struct ib_port_attr attr;