From patchwork Tue Jul 4 00:53:49 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Herbert Xu X-Patchwork-Id: 13300563 X-Patchwork-Delegate: kuba@kernel.org Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (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 5345D620 for ; Tue, 4 Jul 2023 00:54:05 +0000 (UTC) Received: from 167-179-156-38.a7b39c.syd.nbn.aussiebb.net (167-179-156-38.a7b39c.syd.nbn.aussiebb.net [167.179.156.38]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5FF6D137 for ; Mon, 3 Jul 2023 17:54:01 -0700 (PDT) Received: from gwarestrin.arnor.me.apana.org.au ([192.168.103.7]) by fornost.hmeau.com with smtp (Exim 4.94.2 #2 (Debian)) id 1qGUIm-000PWy-K8; Tue, 04 Jul 2023 10:53:57 +1000 Received: by gwarestrin.arnor.me.apana.org.au (sSMTP sendmail emulation); Tue, 04 Jul 2023 08:53:49 +0800 Date: Tue, 4 Jul 2023 08:53:49 +0800 From: Herbert Xu To: Maciej =?utf-8?q?=C5=BBenczykowski?= Cc: Maciej =?utf-8?q?=C5=BBenczykowski?= , Linux Network Development Mailing List , Steffen Klassert , Benedict Wong , Lorenzo Colitti , Yan Yan Subject: [PATCH] xfrm: Silence warnings triggerable by bad packets Message-ID: References: <20230630153759.3349299-1-maze@google.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20230630153759.3349299-1-maze@google.com> X-Spam-Status: No, score=2.7 required=5.0 tests=BAYES_00,HELO_DYNAMIC_IPADDR2, PDS_RDNS_DYNAMIC_FP,RDNS_DYNAMIC,SPF_HELO_NONE,SPF_PASS,TVD_RCVD_IP, T_SCC_BODY_TEXT_LINE,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.6 X-Spam-Level: ** X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net X-Patchwork-Delegate: kuba@kernel.org On Fri, Jun 30, 2023 at 08:37:58AM -0700, Maciej Żenczykowski wrote: > Steffan, this isn't of course a patch meant for inclusion, instead just a WARN_ON hit report. > The patch is simply what prints the following extra info: > > xfrm_prepare_input: XFRM_MODE_SKB_CB(skb)->protocol: 17 > xfrm_inner_mode_encap_remove: x->props.mode: 1 XFRM_MODE_SKB_SB(skb)->protocol:17 > > (note: XFRM_MODE_TUNNEL=1 IPPROTO_UDP=17) Thanks for the report. This patch should fix the warnings: ---8<--- After the elimination of inner modes, a couple of warnings that were previously unreachable can now be triggered by malformed inbound packets. Fix this by: 1. Moving the setting of skb->protocol into the decap functions. 2. Returning -EINVAL when unexpected protocol is seen. Reported-by: Maciej Żenczykowski Fixes: 5f24f41e8ea6 ("xfrm: Remove inner/outer modes from input path") Signed-off-by: Herbert Xu Reviewed-by: Maciej Żenczykowski diff --git a/net/xfrm/xfrm_input.c b/net/xfrm/xfrm_input.c index 815b38080401..d5ee96789d4b 100644 --- a/net/xfrm/xfrm_input.c +++ b/net/xfrm/xfrm_input.c @@ -180,6 +180,8 @@ static int xfrm4_remove_beet_encap(struct xfrm_state *x, struct sk_buff *skb) int optlen = 0; int err = -EINVAL; + skb->protocol = htons(ETH_P_IP); + if (unlikely(XFRM_MODE_SKB_CB(skb)->protocol == IPPROTO_BEETPH)) { struct ip_beet_phdr *ph; int phlen; @@ -232,6 +234,8 @@ static int xfrm4_remove_tunnel_encap(struct xfrm_state *x, struct sk_buff *skb) { int err = -EINVAL; + skb->protocol = htons(ETH_P_IP); + if (!pskb_may_pull(skb, sizeof(struct iphdr))) goto out; @@ -267,6 +271,8 @@ static int xfrm6_remove_tunnel_encap(struct xfrm_state *x, struct sk_buff *skb) { int err = -EINVAL; + skb->protocol = htons(ETH_P_IPV6); + if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) goto out; @@ -296,6 +302,8 @@ static int xfrm6_remove_beet_encap(struct xfrm_state *x, struct sk_buff *skb) int size = sizeof(struct ipv6hdr); int err; + skb->protocol = htons(ETH_P_IPV6); + err = skb_cow_head(skb, size + skb->mac_len); if (err) goto out; @@ -346,6 +354,7 @@ xfrm_inner_mode_encap_remove(struct xfrm_state *x, return xfrm6_remove_tunnel_encap(x, skb); break; } + return -EINVAL; } WARN_ON_ONCE(1); @@ -366,19 +375,6 @@ static int xfrm_prepare_input(struct xfrm_state *x, struct sk_buff *skb) return -EAFNOSUPPORT; } - switch (XFRM_MODE_SKB_CB(skb)->protocol) { - case IPPROTO_IPIP: - case IPPROTO_BEETPH: - skb->protocol = htons(ETH_P_IP); - break; - case IPPROTO_IPV6: - skb->protocol = htons(ETH_P_IPV6); - break; - default: - WARN_ON_ONCE(1); - break; - } - return xfrm_inner_mode_encap_remove(x, skb); }