From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1162188AbeE1KgU (ORCPT ); Mon, 28 May 2018 06:36:20 -0400 Received: from mail.kernel.org ([198.145.29.99]:56640 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1162169AbeE1KgN (ORCPT ); Mon, 28 May 2018 06:36:13 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Daniel Jurgens , Parav Pandit , Leon Romanovsky , Doug Ledford , Sasha Levin Subject: [PATCH 4.9 190/329] IB/core: Fix possible crash to access NULL netdev Date: Mon, 28 May 2018 12:01:59 +0200 Message-Id: <20180528100258.124353694@linuxfoundation.org> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20180528100241.796630982@linuxfoundation.org> References: <20180528100241.796630982@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review 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 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Parav Pandit [ Upstream commit bb7f8f199c354c4cf155b1d6d55f86eaaed7fa5a ] resolved_dev returned might be NULL as ifindex is transient number. Ignoring NULL check of resolved_dev might crash the kernel. Therefore perform NULL check before accessing resolved_dev. Additionally rdma_resolve_ip_route() invokes addr_resolve() which performs check and address translation for loopback ifindex. Therefore, checking it again in rdma_resolve_ip_route() is not helpful. Therefore, the code is simplified to avoid IFF_LOOPBACK check. Fixes: 200298326b27 ("IB/core: Validate route when we init ah") Reviewed-by: Daniel Jurgens Signed-off-by: Parav Pandit Signed-off-by: Leon Romanovsky Signed-off-by: Doug Ledford Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/infiniband/core/sa_query.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) --- a/drivers/infiniband/core/sa_query.c +++ b/drivers/infiniband/core/sa_query.c @@ -1137,10 +1137,9 @@ int ib_init_ah_from_path(struct ib_devic resolved_dev = dev_get_by_index(dev_addr.net, dev_addr.bound_dev_if); - if (resolved_dev->flags & IFF_LOOPBACK) { - dev_put(resolved_dev); - resolved_dev = idev; - dev_hold(resolved_dev); + if (!resolved_dev) { + dev_put(idev); + return -ENODEV; } ndev = ib_get_ndev_from_path(rec); rcu_read_lock();