Patch "xfrm: Silence warnings triggerable by bad packets" has been added to the 6.4-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    xfrm: Silence warnings triggerable by bad packets

to the 6.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     xfrm-silence-warnings-triggerable-by-bad-packets.patch
and it can be found in the queue-6.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit ab53badd71801f64ed76697dabddb70a64818646
Author: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Date:   Tue Jul 4 08:53:49 2023 +0800

    xfrm: Silence warnings triggerable by bad packets
    
    [ Upstream commit 57010b8ece2821a1fdfdba2197d14a022f3769db ]
    
    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<maze@xxxxxxxxxx>
    Fixes: 5f24f41e8ea6 ("xfrm: Remove inner/outer modes from input path")
    Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
    Reviewed-by: Maciej Żenczykowski <maze@xxxxxxxxxx>
    Signed-off-by: Steffen Klassert <steffen.klassert@xxxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

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);
 }