Patch "net: annotate data-races around sk->sk_bind_phc" 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

    net: annotate data-races around sk->sk_bind_phc

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:
     net-annotate-data-races-around-sk-sk_bind_phc.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 1b799e9a0670b2cf155f5463f9b42e791668abaa
Author: Eric Dumazet <edumazet@xxxxxxxxxx>
Date:   Thu Aug 31 13:52:12 2023 +0000

    net: annotate data-races around sk->sk_bind_phc
    
    [ Upstream commit 251cd405a9e6e70b92fe5afbdd17fd5caf9d3266 ]
    
    sk->sk_bind_phc is read locklessly. Add corresponding annotations.
    
    Fixes: d463126e23f1 ("net: sock: extend SO_TIMESTAMPING for PHC binding")
    Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx>
    Cc: Yangbo Lu <yangbo.lu@xxxxxxx>
    Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
    Stable-dep-of: 7f6ca95d16b9 ("net: Implement missing getsockopt(SO_TIMESTAMPING_NEW)")
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/net/core/sock.c b/net/core/sock.c
index 929055bc0cc7b..49b7f252ddae4 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -890,7 +890,7 @@ static int sock_timestamping_bind_phc(struct sock *sk, int phc_index)
 	if (!match)
 		return -EINVAL;
 
-	sk->sk_bind_phc = phc_index;
+	WRITE_ONCE(sk->sk_bind_phc, phc_index);
 
 	return 0;
 }
@@ -1706,7 +1706,7 @@ int sk_getsockopt(struct sock *sk, int level, int optname,
 	case SO_TIMESTAMPING_OLD:
 		lv = sizeof(v.timestamping);
 		v.timestamping.flags = READ_ONCE(sk->sk_tsflags);
-		v.timestamping.bind_phc = sk->sk_bind_phc;
+		v.timestamping.bind_phc = READ_ONCE(sk->sk_bind_phc);
 		break;
 
 	case SO_RCVTIMEO_OLD:
diff --git a/net/socket.c b/net/socket.c
index 9c1fb94b12851..07470724e7358 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -940,7 +940,7 @@ void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk,
 
 		if (tsflags & SOF_TIMESTAMPING_BIND_PHC)
 			hwtstamp = ptp_convert_timestamp(&hwtstamp,
-							 sk->sk_bind_phc);
+							 READ_ONCE(sk->sk_bind_phc));
 
 		if (ktime_to_timespec64_cond(hwtstamp, tss.ts + 2)) {
 			empty = 0;