From patchwork Fri Dec 31 00:36:31 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Ahern X-Patchwork-Id: 12701744 X-Patchwork-Delegate: kuba@kernel.org Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7B2A0C433FE for ; Fri, 31 Dec 2021 00:36:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242385AbhLaAgq (ORCPT ); Thu, 30 Dec 2021 19:36:46 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60116 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242376AbhLaAgo (ORCPT ); Thu, 30 Dec 2021 19:36:44 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 26176C06173F for ; Thu, 30 Dec 2021 16:36:44 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 3F64A61767 for ; Fri, 31 Dec 2021 00:36:41 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E738CC36AED; Fri, 31 Dec 2021 00:36:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1640911000; bh=SADsJkcvRyqA8lYJUXxAYJpuycgbiWK2zcclMETF26I=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=aZtvrGFAh/yIcY0GyN5J+ctfPwmo3rH03J7fpbGt8cS+A+tcGsJshD/6MK+q63KAb sqQX/89Bglbpu6eEWsQFO2g34106XFgJAN0IjJnJeBSnx0Cvx7uarrvm/KGe8W1fHY 8eg4zUXIb5Zv1xtqzgQcKD82aYDtHgIJ/xbOxGSVeUWgQr9KxIdcQWCaqiyH9zaJ6m zPkcPmh6EQK/wO634ZOTthjCAJN60ZLraoW2iUtwLjKC1+QVhyNjo6uSXLIbp7WWVq yygOumYQvW5Q+m9R8M9HVmpCIn2K/PyVMF61GJdiMAFtw7paOJa2mtGgn38sqZm8Yt E8foQFHlf3IbQ== From: David Ahern To: netdev@vger.kernel.org Cc: idosch@idosch.org, David Ahern , syzbot+d4b9a2851cc3ce998741@syzkaller.appspotmail.com, Thomas Graf Subject: [PATCH net 1/5] ipv4: Check attribute length for RTA_GATEWAY in multipath route Date: Thu, 30 Dec 2021 17:36:31 -0700 Message-Id: <20211231003635.91219-2-dsahern@kernel.org> X-Mailer: git-send-email 2.24.3 (Apple Git-128) In-Reply-To: <20211231003635.91219-1-dsahern@kernel.org> References: <20211231003635.91219-1-dsahern@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org syzbot reported uninit-value: ============================================================ BUG: KMSAN: uninit-value in fib_get_nhs+0xac4/0x1f80 net/ipv4/fib_semantics.c:708 fib_get_nhs+0xac4/0x1f80 net/ipv4/fib_semantics.c:708 fib_create_info+0x2411/0x4870 net/ipv4/fib_semantics.c:1453 fib_table_insert+0x45c/0x3a10 net/ipv4/fib_trie.c:1224 inet_rtm_newroute+0x289/0x420 net/ipv4/fib_frontend.c:886 Add helper to validate RTA_GATEWAY length before using the attribute. Fixes: 4e902c57417c ("[IPv4]: FIB configuration using struct fib_config") Reported-by: syzbot+d4b9a2851cc3ce998741@syzkaller.appspotmail.com Signed-off-by: David Ahern Cc: Thomas Graf --- net/ipv4/fib_semantics.c | 29 ++++++++++++++++++++++++++--- 1 file changed, 26 insertions(+), 3 deletions(-) diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c index fde7797b5806..f1caa2c1c041 100644 --- a/net/ipv4/fib_semantics.c +++ b/net/ipv4/fib_semantics.c @@ -662,6 +662,19 @@ static int fib_count_nexthops(struct rtnexthop *rtnh, int remaining, return nhs; } +static int fib_gw_from_attr(__be32 *gw, struct nlattr *nla, + struct netlink_ext_ack *extack) +{ + if (nla_len(nla) < sizeof(*gw)) { + NL_SET_ERR_MSG(extack, "Invalid IPv4 address in RTA_GATEWAY"); + return -EINVAL; + } + + *gw = nla_get_in_addr(nla); + + return 0; +} + /* only called when fib_nh is integrated into fib_info */ static int fib_get_nhs(struct fib_info *fi, struct rtnexthop *rtnh, int remaining, struct fib_config *cfg, @@ -704,7 +717,11 @@ static int fib_get_nhs(struct fib_info *fi, struct rtnexthop *rtnh, return -EINVAL; } if (nla) { - fib_cfg.fc_gw4 = nla_get_in_addr(nla); + ret = fib_gw_from_attr(&fib_cfg.fc_gw4, nla, + extack); + if (ret) + goto errout; + if (fib_cfg.fc_gw4) fib_cfg.fc_gw_family = AF_INET; } else if (nlav) { @@ -902,6 +919,7 @@ int fib_nh_match(struct net *net, struct fib_config *cfg, struct fib_info *fi, attrlen = rtnh_attrlen(rtnh); if (attrlen > 0) { struct nlattr *nla, *nlav, *attrs = rtnh_attrs(rtnh); + int err; nla = nla_find(attrs, attrlen, RTA_GATEWAY); nlav = nla_find(attrs, attrlen, RTA_VIA); @@ -912,12 +930,17 @@ int fib_nh_match(struct net *net, struct fib_config *cfg, struct fib_info *fi, } if (nla) { + __be32 gw; + + err = fib_gw_from_attr(&gw, nla, extack); + if (err) + return err; + if (nh->fib_nh_gw_family != AF_INET || - nla_get_in_addr(nla) != nh->fib_nh_gw4) + gw != nh->fib_nh_gw4) return 1; } else if (nlav) { struct fib_config cfg2; - int err; err = fib_gw_from_via(&cfg2, nlav, extack); if (err)