From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8538234CF7 for ; Wed, 20 Sep 2023 12:02:35 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 05F33C433BB; Wed, 20 Sep 2023 12:02:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1695211355; bh=DpzrbpIz3TBjXexOzFdrUMqFVm1Qa/WL/t79odX4FJs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=DD790DjWzdwP2wvsHVsAvNOriBBCinlLK78f7JR6uSxED3oQvEFF4dwubctOIdhh0 TqkJwtz4mdT5O9BbAYArb63ZDp8siKS9cNhTm/3ebOKgCOQXpeyG98dHGvV3H1Oh4D FIEEoHuwo/4G/9GFBN4wlteXV3/+xsAZ1VtLCloE= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Dan Carpenter , Yan Zhai , Daniel Borkmann , Sasha Levin Subject: [PATCH 4.14 045/186] lwt: Check LWTUNNEL_XMIT_CONTINUE strictly Date: Wed, 20 Sep 2023 13:29:08 +0200 Message-ID: <20230920112838.560178826@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20230920112836.799946261@linuxfoundation.org> References: <20230920112836.799946261@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Yan Zhai [ Upstream commit a171fbec88a2c730b108c7147ac5e7b2f5a02b47 ] LWTUNNEL_XMIT_CONTINUE is implicitly assumed in ip(6)_finish_output2, such that any positive return value from a xmit hook could cause unexpected continue behavior, despite that related skb may have been freed. This could be error-prone for future xmit hook ops. One of the possible errors is to return statuses of dst_output directly. To make the code safer, redefine LWTUNNEL_XMIT_CONTINUE value to distinguish from dst_output statuses and check the continue condition explicitly. Fixes: 3a0af8fd61f9 ("bpf: BPF for lightweight tunnel infrastructure") Suggested-by: Dan Carpenter Signed-off-by: Yan Zhai Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/96b939b85eda00e8df4f7c080f770970a4c5f698.1692326837.git.yan@cloudflare.com Signed-off-by: Sasha Levin --- include/net/lwtunnel.h | 5 ++++- net/ipv4/ip_output.c | 2 +- net/ipv6/ip6_output.c | 2 +- 3 files changed, 6 insertions(+), 3 deletions(-) diff --git a/include/net/lwtunnel.h b/include/net/lwtunnel.h index d747ef975cd80..0ab4647ccc24d 100644 --- a/include/net/lwtunnel.h +++ b/include/net/lwtunnel.h @@ -16,9 +16,12 @@ #define LWTUNNEL_STATE_INPUT_REDIRECT BIT(1) #define LWTUNNEL_STATE_XMIT_REDIRECT BIT(2) +/* LWTUNNEL_XMIT_CONTINUE should be distinguishable from dst_output return + * values (NET_XMIT_xxx and NETDEV_TX_xxx in linux/netdevice.h) for safety. + */ enum { LWTUNNEL_XMIT_DONE, - LWTUNNEL_XMIT_CONTINUE, + LWTUNNEL_XMIT_CONTINUE = 0x100, }; diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c index c5c9dc0f41cbc..c242c412dabc0 100644 --- a/net/ipv4/ip_output.c +++ b/net/ipv4/ip_output.c @@ -221,7 +221,7 @@ static int ip_finish_output2(struct net *net, struct sock *sk, struct sk_buff *s if (lwtunnel_xmit_redirect(dst->lwtstate)) { int res = lwtunnel_xmit(skb); - if (res < 0 || res == LWTUNNEL_XMIT_DONE) + if (res != LWTUNNEL_XMIT_CONTINUE) return res; } diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c index 36647d3211074..c9322e6a1c0cb 100644 --- a/net/ipv6/ip6_output.c +++ b/net/ipv6/ip6_output.c @@ -106,7 +106,7 @@ static int ip6_finish_output2(struct net *net, struct sock *sk, struct sk_buff * if (lwtunnel_xmit_redirect(dst->lwtstate)) { int res = lwtunnel_xmit(skb); - if (res < 0 || res == LWTUNNEL_XMIT_DONE) + if (res != LWTUNNEL_XMIT_CONTINUE) return res; } -- 2.40.1