From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.99]:40960 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1163688AbeE1Kve (ORCPT ); Mon, 28 May 2018 06:51:34 -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 4.14 230/496] IB/core: Fix possible crash to access NULL netdev Date: Mon, 28 May 2018 12:00:15 +0200 Message-Id: <20180528100329.597217534@linuxfoundation.org> In-Reply-To: <20180528100319.498712256@linuxfoundation.org> References: <20180528100319.498712256@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.14-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 @@ -1291,10 +1291,9 @@ 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();