Patch "bpf, sockmap: SK_DROP on attempted redirects of unsupported af_vsock" has been added to the 6.6-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

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

    bpf, sockmap: SK_DROP on attempted redirects of unsupported af_vsock

to the 6.6-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:
     bpf-sockmap-sk_drop-on-attempted-redirects-of-unsupp.patch
and it can be found in the queue-6.6 subdirectory.

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



commit c9cee25c21add629f55c38f961bc85fcafcbfad9
Author: Michal Luczaj <mhal@xxxxxxx>
Date:   Sun Oct 13 18:26:39 2024 +0200

    bpf, sockmap: SK_DROP on attempted redirects of unsupported af_vsock
    
    [ Upstream commit 9c5bd93edf7b8834aecaa7c340b852d5990d7c78 ]
    
    Don't mislead the callers of bpf_{sk,msg}_redirect_{map,hash}(): make sure
    to immediately and visibly fail the forwarding of unsupported af_vsock
    packets.
    
    Fixes: 634f1a7110b4 ("vsock: support sockmap")
    Signed-off-by: Michal Luczaj <mhal@xxxxxxx>
    Signed-off-by: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
    Acked-by: John Fastabend <john.fastabend@xxxxxxxxx>
    Link: https://lore.kernel.org/bpf/20241013-vsock-fixes-for-redir-v2-1-d6577bbfe742@xxxxxxx
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/include/net/sock.h b/include/net/sock.h
index c3961050b8e39..e0be8bd983960 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -2826,6 +2826,11 @@ static inline bool sk_is_stream_unix(const struct sock *sk)
 	return sk->sk_family == AF_UNIX && sk->sk_type == SOCK_STREAM;
 }
 
+static inline bool sk_is_vsock(const struct sock *sk)
+{
+	return sk->sk_family == AF_VSOCK;
+}
+
 /**
  * sk_eat_skb - Release a skb if it is no longer needed
  * @sk: socket to eat this skb from
diff --git a/net/core/sock_map.c b/net/core/sock_map.c
index 2afac40bb83ca..2da881a8e7983 100644
--- a/net/core/sock_map.c
+++ b/net/core/sock_map.c
@@ -644,6 +644,8 @@ BPF_CALL_4(bpf_sk_redirect_map, struct sk_buff *, skb,
 	sk = __sock_map_lookup_elem(map, key);
 	if (unlikely(!sk || !sock_map_redirect_allowed(sk)))
 		return SK_DROP;
+	if ((flags & BPF_F_INGRESS) && sk_is_vsock(sk))
+		return SK_DROP;
 
 	skb_bpf_set_redir(skb, sk, flags & BPF_F_INGRESS);
 	return SK_PASS;
@@ -672,6 +674,8 @@ BPF_CALL_4(bpf_msg_redirect_map, struct sk_msg *, msg,
 		return SK_DROP;
 	if (!(flags & BPF_F_INGRESS) && !sk_is_tcp(sk))
 		return SK_DROP;
+	if (sk_is_vsock(sk))
+		return SK_DROP;
 
 	msg->flags = flags;
 	msg->sk_redir = sk;
@@ -1246,6 +1250,8 @@ BPF_CALL_4(bpf_sk_redirect_hash, struct sk_buff *, skb,
 	sk = __sock_hash_lookup_elem(map, key);
 	if (unlikely(!sk || !sock_map_redirect_allowed(sk)))
 		return SK_DROP;
+	if ((flags & BPF_F_INGRESS) && sk_is_vsock(sk))
+		return SK_DROP;
 
 	skb_bpf_set_redir(skb, sk, flags & BPF_F_INGRESS);
 	return SK_PASS;
@@ -1274,6 +1280,8 @@ BPF_CALL_4(bpf_msg_redirect_hash, struct sk_msg *, msg,
 		return SK_DROP;
 	if (!(flags & BPF_F_INGRESS) && !sk_is_tcp(sk))
 		return SK_DROP;
+	if (sk_is_vsock(sk))
+		return SK_DROP;
 
 	msg->flags = flags;
 	msg->sk_redir = sk;