From 57010b8ece2821a1fdfdba2197d14a022f3769db Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Tue, 4 Jul 2023 08:53:49 +0800 Subject: [PATCH] xfrm: Silence warnings triggerable by bad packets MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Signed-off-by: Steffen Klassert --- net/xfrm/xfrm_input.c | 22 +++++++++------------- 1 file changed, 9 insertions(+), 13 deletions(-) diff --git a/net/xfrm/xfrm_input.c b/net/xfrm/xfrm_input.c index 815b380804011..d5ee96789d4bf 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); }