From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:50400 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732902AbeHDLMM (ORCPT ); Sat, 4 Aug 2018 07:12:12 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Josh Poimboeuf , Jeremy Cline , "David S. Miller" Subject: [PATCH 4.4 116/124] netlink: Fix spectre v1 gadget in netlink_create() Date: Sat, 4 Aug 2018 11:01:45 +0200 Message-Id: <20180804082706.800648641@linuxfoundation.org> In-Reply-To: <20180804082702.434482435@linuxfoundation.org> References: <20180804082702.434482435@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jeremy Cline [ Upstream commit bc5b6c0b62b932626a135f516a41838c510c6eba ] 'protocol' is a user-controlled value, so sanitize it after the bounds check to avoid using it for speculative out-of-bounds access to arrays indexed by it. This addresses the following accesses detected with the help of smatch: * net/netlink/af_netlink.c:654 __netlink_create() warn: potential spectre issue 'nlk_cb_mutex_keys' [w] * net/netlink/af_netlink.c:654 __netlink_create() warn: potential spectre issue 'nlk_cb_mutex_key_strings' [w] * net/netlink/af_netlink.c:685 netlink_create() warn: potential spectre issue 'nl_table' [w] (local cap) Cc: Josh Poimboeuf Signed-off-by: Jeremy Cline Reviewed-by: Josh Poimboeuf Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/netlink/af_netlink.c | 2 ++ 1 file changed, 2 insertions(+) --- a/net/netlink/af_netlink.c +++ b/net/netlink/af_netlink.c @@ -62,6 +62,7 @@ #include #include #include +#include #include #include @@ -654,6 +655,7 @@ static int netlink_create(struct net *ne if (protocol < 0 || protocol >= MAX_LINKS) return -EPROTONOSUPPORT; + protocol = array_index_nospec(protocol, MAX_LINKS); netlink_lock_table(); #ifdef CONFIG_MODULES