Patch "tcp_bpf: Charge receive socket buffer in bpf_tcp_ingress()" has been added to the 5.15-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

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

    tcp_bpf: Charge receive socket buffer in bpf_tcp_ingress()

to the 5.15-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:
     tcp_bpf-charge-receive-socket-buffer-in-bpf_tcp_ingr.patch
and it can be found in the queue-5.15 subdirectory.

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



commit 88e46ac4db8980e218bc750de94d14deb69364d7
Author: Cong Wang <cong.wang@xxxxxxxxxxxxx>
Date:   Tue Dec 10 01:20:38 2024 +0000

    tcp_bpf: Charge receive socket buffer in bpf_tcp_ingress()
    
    [ Upstream commit 54f89b3178d5448dd4457afbb98fc1ab99090a65 ]
    
    When bpf_tcp_ingress() is called, the skmsg is being redirected to the
    ingress of the destination socket. Therefore, we should charge its
    receive socket buffer, instead of sending socket buffer.
    
    Because sk_rmem_schedule() tests pfmemalloc of skb, we need to
    introduce a wrapper and call it for skmsg.
    
    Fixes: 604326b41a6f ("bpf, sockmap: convert to generic sk_msg interface")
    Signed-off-by: Cong Wang <cong.wang@xxxxxxxxxxxxx>
    Signed-off-by: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
    Reviewed-by: John Fastabend <john.fastabend@xxxxxxxxx>
    Link: https://lore.kernel.org/bpf/20241210012039.1669389-2-zijianzhang@xxxxxxxxxxxxx
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/include/net/sock.h b/include/net/sock.h
index 1680d6dc4d19..ca3cc2b325d7 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -1570,7 +1570,7 @@ static inline bool sk_wmem_schedule(struct sock *sk, int size)
 }
 
 static inline bool
-sk_rmem_schedule(struct sock *sk, struct sk_buff *skb, int size)
+__sk_rmem_schedule(struct sock *sk, int size, bool pfmemalloc)
 {
 	int delta;
 
@@ -1578,7 +1578,13 @@ sk_rmem_schedule(struct sock *sk, struct sk_buff *skb, int size)
 		return true;
 	delta = size - sk->sk_forward_alloc;
 	return delta <= 0 || __sk_mem_schedule(sk, delta, SK_MEM_RECV) ||
-		skb_pfmemalloc(skb);
+	       pfmemalloc;
+}
+
+static inline bool
+sk_rmem_schedule(struct sock *sk, struct sk_buff *skb, int size)
+{
+	return __sk_rmem_schedule(sk, size, skb_pfmemalloc(skb));
 }
 
 static inline void sk_mem_reclaim(struct sock *sk)
diff --git a/net/ipv4/tcp_bpf.c b/net/ipv4/tcp_bpf.c
index f2ae1e51e59f..dc1291827381 100644
--- a/net/ipv4/tcp_bpf.c
+++ b/net/ipv4/tcp_bpf.c
@@ -31,7 +31,7 @@ static int bpf_tcp_ingress(struct sock *sk, struct sk_psock *psock,
 		sge = sk_msg_elem(msg, i);
 		size = (apply && apply_bytes < sge->length) ?
 			apply_bytes : sge->length;
-		if (!sk_wmem_schedule(sk, size)) {
+		if (!__sk_rmem_schedule(sk, size, false)) {
 			if (!copied)
 				ret = -ENOMEM;
 			break;