From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,UNPARSEABLE_RELAY, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C16E7C282C4 for ; Tue, 12 Feb 2019 20:24:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 88F5721904 for ; Tue, 12 Feb 2019 20:24:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730909AbfBLUYO (ORCPT ); Tue, 12 Feb 2019 15:24:14 -0500 Received: from mail-il-dmz.mellanox.com ([193.47.165.129]:47802 "EHLO mellanox.co.il" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727659AbfBLUYO (ORCPT ); Tue, 12 Feb 2019 15:24:14 -0500 Received: from Internal Mail-Server by MTLPINE1 (envelope-from parav@mellanox.com) with ESMTPS (AES256-SHA encrypted); 12 Feb 2019 22:24:12 +0200 Received: from sw-mtx-036.mtx.labs.mlnx (sw-mtx-036.mtx.labs.mlnx [10.12.150.149]) by labmailer.mlnx (8.13.8/8.13.8) with ESMTP id x1CKOAZG018611; Tue, 12 Feb 2019 22:24:11 +0200 From: Parav Pandit To: jiri@mellanox.com, davem@davemloft.net, netdev@vger.kernel.org Cc: parav@mellanox.com Subject: [PATCHv2 net-next 2/2] devlink: Fix list access without lock while reading region Date: Tue, 12 Feb 2019 14:24:08 -0600 Message-Id: <1550003048-28985-1-git-send-email-parav@mellanox.com> X-Mailer: git-send-email 1.8.3.1 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org While finding the devlink device during region reading, devlink device list is accessed and devlink device is returned without holding a lock. This could lead to use-after-free accesses. While at it, add lockdep assert to ensure that all future callers hold the lock when calling devlink_get_from_attrs(). Fixes: 4e54795a27f5 ("devlink: Add support for region snapshot read command") Signed-off-by: Parav Pandit Acked-by: Jiri Pirko --- v0->v1: - Fixed typo from user to use --- net/core/devlink.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/net/core/devlink.c b/net/core/devlink.c index 312084f..1d7502a 100644 --- a/net/core/devlink.c +++ b/net/core/devlink.c @@ -116,6 +116,8 @@ static struct devlink *devlink_get_from_attrs(struct net *net, busname = nla_data(attrs[DEVLINK_ATTR_BUS_NAME]); devname = nla_data(attrs[DEVLINK_ATTR_DEV_NAME]); + lockdep_assert_held(&devlink_mutex); + list_for_each_entry(devlink, &devlink_list, list) { if (strcmp(devlink->dev->bus->name, busname) == 0 && strcmp(dev_name(devlink->dev), devname) == 0 && @@ -3645,13 +3647,13 @@ static int devlink_nl_cmd_region_read_dumpit(struct sk_buff *skb, if (err) goto out_free; + mutex_lock(&devlink_mutex); devlink = devlink_get_from_attrs(sock_net(cb->skb->sk), attrs); if (IS_ERR(devlink)) { err = PTR_ERR(devlink); - goto out_free; + goto out_dev; } - mutex_lock(&devlink_mutex); mutex_lock(&devlink->lock); if (!attrs[DEVLINK_ATTR_REGION_NAME] || @@ -3729,6 +3731,7 @@ static int devlink_nl_cmd_region_read_dumpit(struct sk_buff *skb, genlmsg_cancel(skb, hdr); out_unlock: mutex_unlock(&devlink->lock); +out_dev: mutex_unlock(&devlink_mutex); out_free: kfree(attrs); -- 1.8.3.1