Patch "inet: factor out locked section of inet_accept() in a new helper" has been added to the 6.1-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

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

    inet: factor out locked section of inet_accept() in a new helper

to the 6.1-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:
     inet-factor-out-locked-section-of-inet_accept-in-a-n.patch
and it can be found in the queue-6.1 subdirectory.

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



commit 59bb2e4f0e86ea10d689e90248e0a7ffbb034535
Author: Paolo Abeni <pabeni@xxxxxxxxxx>
Date:   Wed May 17 12:16:14 2023 -0700

    inet: factor out locked section of inet_accept() in a new helper
    
    [ Upstream commit 711bdd5141d81ab21dbe0a533024d594210d5ba4 ]
    
    No functional changes intended. The new helper will be used
    by the MPTCP protocol in the next patch to avoid duplicating
    a few LoC.
    
    Signed-off-by: Paolo Abeni <pabeni@xxxxxxxxxx>
    Reviewed-by: Matthieu Baerts <matthieu.baerts@xxxxxxxxxxxx>
    Signed-off-by: Mat Martineau <martineau@xxxxxxxxxx>
    Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
    Stable-dep-of: 26afda78cda3 ("net: relax socket state check at accept time.")
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/include/net/inet_common.h b/include/net/inet_common.h
index 4673bbfd2811f..a75333342c4ec 100644
--- a/include/net/inet_common.h
+++ b/include/net/inet_common.h
@@ -31,6 +31,8 @@ int inet_dgram_connect(struct socket *sock, struct sockaddr *uaddr,
 		       int addr_len, int flags);
 int inet_accept(struct socket *sock, struct socket *newsock, int flags,
 		bool kern);
+void __inet_accept(struct socket *sock, struct socket *newsock,
+		   struct sock *newsk);
 int inet_send_prepare(struct sock *sk);
 int inet_sendmsg(struct socket *sock, struct msghdr *msg, size_t size);
 void inet_splice_eof(struct socket *sock);
diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index 9408dc3bb42d3..56d4ec955b851 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -744,6 +744,20 @@ int inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
 }
 EXPORT_SYMBOL(inet_stream_connect);
 
+void __inet_accept(struct socket *sock, struct socket *newsock, struct sock *newsk)
+{
+	sock_rps_record_flow(newsk);
+	WARN_ON(!((1 << newsk->sk_state) &
+		  (TCPF_ESTABLISHED | TCPF_SYN_RECV |
+		  TCPF_CLOSE_WAIT | TCPF_CLOSE)));
+
+	if (test_bit(SOCK_SUPPORT_ZC, &sock->flags))
+		set_bit(SOCK_SUPPORT_ZC, &newsock->flags);
+	sock_graft(newsk, newsock);
+
+	newsock->state = SS_CONNECTED;
+}
+
 /*
  *	Accept a pending connection. The TCP layer now gives BSD semantics.
  */
@@ -757,24 +771,12 @@ int inet_accept(struct socket *sock, struct socket *newsock, int flags,
 	/* IPV6_ADDRFORM can change sk->sk_prot under us. */
 	sk2 = READ_ONCE(sk1->sk_prot)->accept(sk1, flags, &err, kern);
 	if (!sk2)
-		goto do_err;
+		return err;
 
 	lock_sock(sk2);
-
-	sock_rps_record_flow(sk2);
-	WARN_ON(!((1 << sk2->sk_state) &
-		  (TCPF_ESTABLISHED | TCPF_SYN_RECV |
-		  TCPF_CLOSE_WAIT | TCPF_CLOSE)));
-
-	if (test_bit(SOCK_SUPPORT_ZC, &sock->flags))
-		set_bit(SOCK_SUPPORT_ZC, &newsock->flags);
-	sock_graft(sk2, newsock);
-
-	newsock->state = SS_CONNECTED;
-	err = 0;
+	__inet_accept(sock, newsock, sk2);
 	release_sock(sk2);
-do_err:
-	return err;
+	return 0;
 }
 EXPORT_SYMBOL(inet_accept);