net: make sk->sk_sndtimeo lockless

Followup of commit 285975dd6742 ("net: annotate data-races around
sk->sk_{rcv|snd}timeo").

Remove lock_sock()/release_sock() from sock_set_sndtimeo(),
and add READ_ONCE()/WRITE_ONCE() where it is needed.

Also SO_SNDTIMEO_OLD and SO_SNDTIMEO_NEW can call sock_set_timeout()
without holding the socket lock.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250620155536.335520-2-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/include/net/sock.h b/include/net/sock.h
index bbd97fbc5935cd44eb2b23c205473856cda44451..b08e36bf96694235e54eec90a7abf8fcee6a55c6 100644 (file)
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -2601,7 +2601,7 @@ static inline long sock_rcvtimeo(const struct sock *sk, bool noblock)
 
 static inline long sock_sndtimeo(const struct sock *sk, bool noblock)
 {
-       return noblock ? 0 : sk->sk_sndtimeo;
+       return noblock ? 0 : READ_ONCE(sk->sk_sndtimeo);
 }
 
 static inline int sock_rcvlowat(const struct sock *sk, int waitall, int len)

diff --git a/net/bluetooth/iso.c b/net/bluetooth/iso.c
index 3c2c98eecc62675be10161ba40046be871bb3bb7..34e89bb5f3841b67c753a07ec12fe1c5bdd6f646 100644 (file)
--- a/net/bluetooth/iso.c
+++ b/net/bluetooth/iso.c
@@ -413,7 +413,7 @@ static int iso_connect_bis(struct sock *sk)
                sk->sk_state = BT_CONNECT;
        } else {
                sk->sk_state = BT_CONNECT;
-               iso_sock_set_timer(sk, sk->sk_sndtimeo);
+               iso_sock_set_timer(sk, READ_ONCE(sk->sk_sndtimeo));
        }
 
        release_sock(sk);
@@ -503,7 +503,7 @@ static int iso_connect_cis(struct sock *sk)
                sk->sk_state = BT_CONNECT;
        } else {
                sk->sk_state = BT_CONNECT;
-               iso_sock_set_timer(sk, sk->sk_sndtimeo);
+               iso_sock_set_timer(sk, READ_ONCE(sk->sk_sndtimeo));
        }
 
        release_sock(sk);

diff --git a/net/bluetooth/l2cap_sock.c b/net/bluetooth/l2cap_sock.c
index 5aa55fa695943a79bcdd38e5661af9b637fe18ba..113656489db5d8a094d25599506d531b79285036 100644 (file)
--- a/net/bluetooth/l2cap_sock.c
+++ b/net/bluetooth/l2cap_sock.c
@@ -255,7 +255,7 @@ static int l2cap_sock_connect(struct socket *sock, struct sockaddr *addr,
 
        err = l2cap_chan_connect(chan, la.l2_psm, __le16_to_cpu(la.l2_cid),
                                 &la.l2_bdaddr, la.l2_bdaddr_type,
-                                sk->sk_sndtimeo);
+                                READ_ONCE(sk->sk_sndtimeo));
        if (err)
                return err;
 
@@ -1725,7 +1725,7 @@ static long l2cap_sock_get_sndtimeo_cb(struct l2cap_chan *chan)
 {
        struct sock *sk = chan->data;
 
-       return sk->sk_sndtimeo;
+       return READ_ONCE(sk->sk_sndtimeo);
 }
 
 static struct pid *l2cap_sock_get_peer_pid_cb(struct l2cap_chan *chan)

diff --git a/net/bluetooth/sco.c b/net/bluetooth/sco.c
index 2945d27e75dce6839e404906f13eb1765c80249a..d382d980fd9a73bac80f8fd9b2702c2e85d29688 100644 (file)
--- a/net/bluetooth/sco.c
+++ b/net/bluetooth/sco.c
@@ -338,7 +338,7 @@ static int sco_connect(struct sock *sk)
 
        hcon = hci_connect_sco(hdev, type, &sco_pi(sk)->dst,
                               sco_pi(sk)->setting, &sco_pi(sk)->codec,
-                              sk->sk_sndtimeo);
+                              READ_ONCE(sk->sk_sndtimeo));
        if (IS_ERR(hcon)) {
                err = PTR_ERR(hcon);
                goto unlock;
@@ -367,7 +367,7 @@ static int sco_connect(struct sock *sk)
                sk->sk_state = BT_CONNECTED;
        } else {
                sk->sk_state = BT_CONNECT;
-               sco_sock_set_timer(sk, sk->sk_sndtimeo);
+               sco_sock_set_timer(sk, READ_ONCE(sk->sk_sndtimeo));
        }
 
        release_sock(sk);

diff --git a/net/core/sock.c b/net/core/sock.c
index ceb74ceecb6c0dd836f25e15659c7ee8d71565eb..b0b5a0a76045568d520e2bae2a1d489c5399a053 100644 (file)
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -818,12 +818,10 @@ EXPORT_SYMBOL(sock_set_priority);
 
 void sock_set_sndtimeo(struct sock *sk, s64 secs)
 {
-       lock_sock(sk);
        if (secs && secs < MAX_SCHEDULE_TIMEOUT / HZ - 1)
                WRITE_ONCE(sk->sk_sndtimeo, secs * HZ);
        else
                WRITE_ONCE(sk->sk_sndtimeo, MAX_SCHEDULE_TIMEOUT);
-       release_sock(sk);
 }
 EXPORT_SYMBOL(sock_set_sndtimeo);
 
@@ -1287,6 +1285,10 @@ int sk_setsockopt(struct sock *sk, int level, int optname,
        case SO_DEVMEM_DONTNEED:
                return sock_devmem_dontneed(sk, optval, optlen);
 #endif
+       case SO_SNDTIMEO_OLD:
+       case SO_SNDTIMEO_NEW:
+               return sock_set_timeout(&sk->sk_sndtimeo, optval,
+                                       optlen, optname == SO_SNDTIMEO_OLD);
        }
 
        sockopt_lock_sock(sk);
@@ -1448,12 +1450,6 @@ set_sndbuf:
                                       optlen, optname == SO_RCVTIMEO_OLD);
                break;
 
-       case SO_SNDTIMEO_OLD:
-       case SO_SNDTIMEO_NEW:
-               ret = sock_set_timeout(&sk->sk_sndtimeo, optval,
-                                      optlen, optname == SO_SNDTIMEO_OLD);
-               break;
-
        case SO_ATTACH_FILTER: {
                struct sock_fprog fprog;
 

diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index aa6400811018e0835ad91990f363c69d439c5aa0..5b690a4d29692e487605fb9217d55e9cac66652b 100644 (file)
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -9493,7 +9493,7 @@ void sctp_copy_sock(struct sock *newsk, struct sock *sk,
        newsk->sk_rcvbuf = sk->sk_rcvbuf;
        newsk->sk_lingertime = sk->sk_lingertime;
        newsk->sk_rcvtimeo = sk->sk_rcvtimeo;
-       newsk->sk_sndtimeo = sk->sk_sndtimeo;
+       newsk->sk_sndtimeo = READ_ONCE(sk->sk_sndtimeo);
        newsk->sk_rxhash = sk->sk_rxhash;
 
        newinet = inet_sk(newsk);

diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
index 3760131f1484503323b2843fe5304a2283c10c4d..6375a86fe2b5f4e9c5aa9f2a71650e5708692be7 100644 (file)
--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -486,7 +486,7 @@ static void smc_copy_sock_settings(struct sock *nsk, struct sock *osk,
 {
        /* options we don't get control via setsockopt for */
        nsk->sk_type = osk->sk_type;
-       nsk->sk_sndtimeo = osk->sk_sndtimeo;
+       nsk->sk_sndtimeo = READ_ONCE(osk->sk_sndtimeo);
        nsk->sk_rcvtimeo = osk->sk_rcvtimeo;
        nsk->sk_mark = READ_ONCE(osk->sk_mark);
        nsk->sk_priority = READ_ONCE(osk->sk_priority);
@@ -1585,7 +1585,7 @@ static void smc_connect_work(struct work_struct *work)
 {
        struct smc_sock *smc = container_of(work, struct smc_sock,
                                            connect_work);
-       long timeo = smc->sk.sk_sndtimeo;
+       long timeo = READ_ONCE(smc->sk.sk_sndtimeo);
        int rc = 0;
 
        if (!timeo)