net: annotate data-races around sock->ops

IPV6_ADDRFORM socket option is evil, because it can change sock->ops
while other threads might read it. Same issue for sk->sk_family
being set to AF_INET.

Adding READ_ONCE() over sock->ops reads is needed for sockets
that might be impacted by IPV6_ADDRFORM.

Note that mptcp_is_tcpsk() can also overwrite sock->ops.

Adding annotations for all sk->sk_family reads will require
more patches :/

BUG: KCSAN: data-race in ____sys_sendmsg / do_ipv6_setsockopt

write to 0xffff888109f24ca0 of 8 bytes by task 4470 on cpu 0:
do_ipv6_setsockopt+0x2c5e/0x2ce0 net/ipv6/ipv6_sockglue.c:491
ipv6_setsockopt+0x57/0x130 net/ipv6/ipv6_sockglue.c:1012
udpv6_setsockopt+0x95/0xa0 net/ipv6/udp.c:1690
sock_common_setsockopt+0x61/0x70 net/core/sock.c:3663
__sys_setsockopt+0x1c3/0x230 net/socket.c:2273
__do_sys_setsockopt net/socket.c:2284 [inline]
__se_sys_setsockopt net/socket.c:2281 [inline]
__x64_sys_setsockopt+0x66/0x80 net/socket.c:2281
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd

read to 0xffff888109f24ca0 of 8 bytes by task 4469 on cpu 1:
sock_sendmsg_nosec net/socket.c:724 [inline]
sock_sendmsg net/socket.c:747 [inline]
____sys_sendmsg+0x349/0x4c0 net/socket.c:2503
___sys_sendmsg net/socket.c:2557 [inline]
__sys_sendmmsg+0x263/0x500 net/socket.c:2643
__do_sys_sendmmsg net/socket.c:2672 [inline]
__se_sys_sendmmsg net/socket.c:2669 [inline]
__x64_sys_sendmmsg+0x57/0x60 net/socket.c:2669
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0xffffffff850e32b8 -> 0xffffffff850da890

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 4469 Comm: syz-executor.1 Not tainted 6.4.0-rc5-syzkaller-00313-g4c605260bc60 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/25/2023

Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://lore.kernel.org/r/20230808135809.2300241-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/include/linux/net.h b/include/linux/net.h
index 41c608c..c9b4a63 100644 (file)
--- a/include/linux/net.h
+++ b/include/linux/net.h
@@ -123,7 +123,7 @@ struct socket {
 
        struct file             *file;
        struct sock             *sk;
-       const struct proto_ops  *ops;
+       const struct proto_ops  *ops; /* Might change with IPV6_ADDRFORM or MPTCP. */
 
        struct socket_wq        wq;
 };

diff --git a/net/9p/trans_fd.c b/net/9p/trans_fd.c
index 00b6846..c4015f3 100644 (file)
--- a/net/9p/trans_fd.c
+++ b/net/9p/trans_fd.c
@@ -1019,7 +1019,7 @@ p9_fd_create_tcp(struct p9_client *client, const char *addr, char *args)
                }
        }
 
-       err = csocket->ops->connect(csocket,
+       err = READ_ONCE(csocket->ops)->connect(csocket,
                                    (struct sockaddr *)&sin_server,
                                    sizeof(struct sockaddr_in), 0);
        if (err < 0) {
@@ -1060,7 +1060,7 @@ p9_fd_create_unix(struct p9_client *client, const char *addr, char *args)
 
                return err;
        }
-       err = csocket->ops->connect(csocket, (struct sockaddr *)&sun_server,
+       err = READ_ONCE(csocket->ops)->connect(csocket, (struct sockaddr *)&sun_server,
                        sizeof(struct sockaddr_un) - 1, 0);
        if (err < 0) {
                pr_err("%s (%d): problem connecting socket: %s: %d\n",

diff --git a/net/core/scm.c b/net/core/scm.c
index 3cd7dd3..880027e 100644 (file)
--- a/net/core/scm.c
+++ b/net/core/scm.c
@@ -130,6 +130,7 @@ EXPORT_SYMBOL(__scm_destroy);
 
 int __scm_send(struct socket *sock, struct msghdr *msg, struct scm_cookie *p)
 {
+       const struct proto_ops *ops = READ_ONCE(sock->ops);
        struct cmsghdr *cmsg;
        int err;
 
@@ -153,7 +154,7 @@ int __scm_send(struct socket *sock, struct msghdr *msg, struct scm_cookie *p)
                switch (cmsg->cmsg_type)
                {
                case SCM_RIGHTS:
-                       if (!sock->ops || sock->ops->family != PF_UNIX)
+                       if (!ops || ops->family != PF_UNIX)
                                goto error;
                        err=scm_fp_copy(cmsg, &p->fp);
                        if (err<0)

diff --git a/net/core/skmsg.c b/net/core/skmsg.c
index a29508e..e6dfc84 100644 (file)
--- a/net/core/skmsg.c
+++ b/net/core/skmsg.c
@@ -1198,13 +1198,17 @@ out:
 static void sk_psock_verdict_data_ready(struct sock *sk)
 {
        struct socket *sock = sk->sk_socket;
+       const struct proto_ops *ops;
        int copied;
 
        trace_sk_data_ready(sk);
 
-       if (unlikely(!sock || !sock->ops || !sock->ops->read_skb))
+       if (unlikely(!sock))
                return;
-       copied = sock->ops->read_skb(sk, sk_psock_verdict_recv);
+       ops = READ_ONCE(sock->ops);
+       if (!ops || !ops->read_skb)
+               return;
+       copied = ops->read_skb(sk, sk_psock_verdict_recv);
        if (copied >= 0) {
                struct sk_psock *psock;
 

diff --git a/net/core/sock.c b/net/core/sock.c
index 4991580..51f7d94 100644 (file)
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -1277,14 +1277,19 @@ set_sndbuf:
                break;
 
        case SO_RCVLOWAT:
+               {
+               int (*set_rcvlowat)(struct sock *sk, int val) = NULL;
+
                if (val < 0)
                        val = INT_MAX;
-               if (sock && sock->ops->set_rcvlowat)
-                       ret = sock->ops->set_rcvlowat(sk, val);
+               if (sock)
+                       set_rcvlowat = READ_ONCE(sock->ops)->set_rcvlowat;
+               if (set_rcvlowat)
+                       ret = set_rcvlowat(sk, val);
                else
                        WRITE_ONCE(sk->sk_rcvlowat, val ? : 1);
                break;
-
+               }
        case SO_RCVTIMEO_OLD:
        case SO_RCVTIMEO_NEW:
                ret = sock_set_timeout(&sk->sk_rcvtimeo, optval,
@@ -1379,11 +1384,16 @@ set_sndbuf:
                break;
 
        case SO_PEEK_OFF:
-               if (sock->ops->set_peek_off)
-                       ret = sock->ops->set_peek_off(sk, val);
+               {
+               int (*set_peek_off)(struct sock *sk, int val);
+
+               set_peek_off = READ_ONCE(sock->ops)->set_peek_off;
+               if (set_peek_off)
+                       ret = set_peek_off(sk, val);
                else
                        ret = -EOPNOTSUPP;
                break;
+               }
 
        case SO_NOFCS:
                sock_valbool_flag(sk, SOCK_NOFCS, valbool);
@@ -1816,7 +1826,7 @@ int sk_getsockopt(struct sock *sk, int level, int optname,
        {
                struct sockaddr_storage address;
 
-               lv = sock->ops->getname(sock, (struct sockaddr *)&address, 2);
+               lv = READ_ONCE(sock->ops)->getname(sock, (struct sockaddr *)&address, 2);
                if (lv < 0)
                        return -ENOTCONN;
                if (lv < len)
@@ -1858,7 +1868,7 @@ int sk_getsockopt(struct sock *sk, int level, int optname,
                break;
 
        case SO_PEEK_OFF:
-               if (!sock->ops->set_peek_off)
+               if (!READ_ONCE(sock->ops)->set_peek_off)
                        return -EOPNOTSUPP;
 
                v.val = READ_ONCE(sk->sk_peek_off);

diff --git a/net/ipv6/ipv6_sockglue.c b/net/ipv6/ipv6_sockglue.c
index ae818ff..ca37715 100644 (file)
--- a/net/ipv6/ipv6_sockglue.c
+++ b/net/ipv6/ipv6_sockglue.c
@@ -474,8 +474,8 @@ int do_ipv6_setsockopt(struct sock *sk, int level, int optname,
                                WRITE_ONCE(sk->sk_prot, &tcp_prot);
                                /* Paired with READ_ONCE() in tcp_(get|set)sockopt() */
                                WRITE_ONCE(icsk->icsk_af_ops, &ipv4_specific);
-                               sk->sk_socket->ops = &inet_stream_ops;
-                               sk->sk_family = PF_INET;
+                               WRITE_ONCE(sk->sk_socket->ops, &inet_stream_ops);
+                               WRITE_ONCE(sk->sk_family, PF_INET);
                                tcp_sync_mss(sk, icsk->icsk_pmtu_cookie);
                        } else {
                                struct proto *prot = &udp_prot;
@@ -488,8 +488,8 @@ int do_ipv6_setsockopt(struct sock *sk, int level, int optname,
 
                                /* Paired with READ_ONCE(sk->sk_prot) in inet6_dgram_ops */
                                WRITE_ONCE(sk->sk_prot, prot);
-                               sk->sk_socket->ops = &inet_dgram_ops;
-                               sk->sk_family = PF_INET;
+                               WRITE_ONCE(sk->sk_socket->ops, &inet_dgram_ops);
+                               WRITE_ONCE(sk->sk_family, PF_INET);
                        }
 
                        /* Disable all options not to allocate memory anymore,

diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index 65ee949..1c079e8 100644 (file)
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -67,11 +67,11 @@ static bool mptcp_is_tcpsk(struct sock *sk)
                 * Hand the socket over to tcp so all further socket ops
                 * bypass mptcp.
                 */
-               sock->ops = &inet_stream_ops;
+               WRITE_ONCE(sock->ops, &inet_stream_ops);
                return true;
 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
        } else if (unlikely(sk->sk_prot == &tcpv6_prot)) {
-               sock->ops = &inet6_stream_ops;
+               WRITE_ONCE(sock->ops, &inet6_stream_ops);
                return true;
 #endif
        }
@@ -3683,7 +3683,7 @@ static int mptcp_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
                goto unlock;
        }
 
-       err = ssock->ops->bind(ssock, uaddr, addr_len);
+       err = READ_ONCE(ssock->ops)->bind(ssock, uaddr, addr_len);
        if (!err)
                mptcp_copy_inaddrs(sock->sk, ssock->sk);
 
@@ -3717,7 +3717,7 @@ static int mptcp_listen(struct socket *sock, int backlog)
        inet_sk_state_store(sk, TCP_LISTEN);
        sock_set_flag(sk, SOCK_RCU_FREE);
 
-       err = ssock->ops->listen(ssock, backlog);
+       err = READ_ONCE(ssock->ops)->listen(ssock, backlog);
        inet_sk_state_store(sk, inet_sk_state_load(ssock->sk));
        if (!err) {
                sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);

diff --git a/net/socket.c b/net/socket.c
index 2b0e54b..5d4e375 100644 (file)
--- a/net/socket.c
+++ b/net/socket.c
@@ -136,9 +136,10 @@ static void sock_splice_eof(struct file *file);
 static void sock_show_fdinfo(struct seq_file *m, struct file *f)
 {
        struct socket *sock = f->private_data;
+       const struct proto_ops *ops = READ_ONCE(sock->ops);
 
-       if (sock->ops->show_fdinfo)
-               sock->ops->show_fdinfo(m, sock);
+       if (ops->show_fdinfo)
+               ops->show_fdinfo(m, sock);
 }
 #else
 #define sock_show_fdinfo NULL
@@ -646,12 +647,14 @@ EXPORT_SYMBOL(sock_alloc);
 
 static void __sock_release(struct socket *sock, struct inode *inode)
 {
-       if (sock->ops) {
-               struct module *owner = sock->ops->owner;
+       const struct proto_ops *ops = READ_ONCE(sock->ops);
+
+       if (ops) {
+               struct module *owner = ops->owner;
 
                if (inode)
                        inode_lock(inode);
-               sock->ops->release(sock);
+               ops->release(sock);
                sock->sk = NULL;
                if (inode)
                        inode_unlock(inode);
@@ -722,7 +725,7 @@ static noinline void call_trace_sock_send_length(struct sock *sk, int ret,
 
 static inline int sock_sendmsg_nosec(struct socket *sock, struct msghdr *msg)
 {
-       int ret = INDIRECT_CALL_INET(sock->ops->sendmsg, inet6_sendmsg,
+       int ret = INDIRECT_CALL_INET(READ_ONCE(sock->ops)->sendmsg, inet6_sendmsg,
                                     inet_sendmsg, sock, msg,
                                     msg_data_left(msg));
        BUG_ON(ret == -EIOCBQUEUED);
@@ -786,13 +789,14 @@ int kernel_sendmsg_locked(struct sock *sk, struct msghdr *msg,
                          struct kvec *vec, size_t num, size_t size)
 {
        struct socket *sock = sk->sk_socket;
+       const struct proto_ops *ops = READ_ONCE(sock->ops);
 
-       if (!sock->ops->sendmsg_locked)
+       if (!ops->sendmsg_locked)
                return sock_no_sendmsg_locked(sk, msg, size);
 
        iov_iter_kvec(&msg->msg_iter, ITER_SOURCE, vec, num, size);
 
-       return sock->ops->sendmsg_locked(sk, msg, msg_data_left(msg));
+       return ops->sendmsg_locked(sk, msg, msg_data_left(msg));
 }
 EXPORT_SYMBOL(kernel_sendmsg_locked);
 
@@ -1017,7 +1021,8 @@ static noinline void call_trace_sock_recv_length(struct sock *sk, int ret, int f
 static inline int sock_recvmsg_nosec(struct socket *sock, struct msghdr *msg,
                                     int flags)
 {
-       int ret = INDIRECT_CALL_INET(sock->ops->recvmsg, inet6_recvmsg,
+       int ret = INDIRECT_CALL_INET(READ_ONCE(sock->ops)->recvmsg,
+                                    inet6_recvmsg,
                                     inet_recvmsg, sock, msg,
                                     msg_data_left(msg), flags);
        if (trace_sock_recv_length_enabled())
@@ -1072,19 +1077,23 @@ static ssize_t sock_splice_read(struct file *file, loff_t *ppos,
                                unsigned int flags)
 {
        struct socket *sock = file->private_data;
+       const struct proto_ops *ops;
 
-       if (unlikely(!sock->ops->splice_read))
+       ops = READ_ONCE(sock->ops);
+       if (unlikely(!ops->splice_read))
                return copy_splice_read(file, ppos, pipe, len, flags);
 
-       return sock->ops->splice_read(sock, ppos, pipe, len, flags);
+       return ops->splice_read(sock, ppos, pipe, len, flags);
 }
 
 static void sock_splice_eof(struct file *file)
 {
        struct socket *sock = file->private_data;
+       const struct proto_ops *ops;
 
-       if (sock->ops->splice_eof)
-               sock->ops->splice_eof(sock);
+       ops = READ_ONCE(sock->ops);
+       if (ops->splice_eof)
+               ops->splice_eof(sock);
 }
 
 static ssize_t sock_read_iter(struct kiocb *iocb, struct iov_iter *to)
@@ -1181,13 +1190,14 @@ EXPORT_SYMBOL(vlan_ioctl_set);
 static long sock_do_ioctl(struct net *net, struct socket *sock,
                          unsigned int cmd, unsigned long arg)
 {
+       const struct proto_ops *ops = READ_ONCE(sock->ops);
        struct ifreq ifr;
        bool need_copyout;
        int err;
        void __user *argp = (void __user *)arg;
        void __user *data;
 
-       err = sock->ops->ioctl(sock, cmd, arg);
+       err = ops->ioctl(sock, cmd, arg);
 
        /*
         * If this ioctl is unknown try to hand it down
@@ -1216,6 +1226,7 @@ static long sock_do_ioctl(struct net *net, struct socket *sock,
 
 static long sock_ioctl(struct file *file, unsigned cmd, unsigned long arg)
 {
+       const struct proto_ops  *ops;
        struct socket *sock;
        struct sock *sk;
        void __user *argp = (void __user *)arg;
@@ -1223,6 +1234,7 @@ static long sock_ioctl(struct file *file, unsigned cmd, unsigned long arg)
        struct net *net;
 
        sock = file->private_data;
+       ops = READ_ONCE(sock->ops);
        sk = sock->sk;
        net = sock_net(sk);
        if (unlikely(cmd >= SIOCDEVPRIVATE && cmd <= (SIOCDEVPRIVATE + 15))) {
@@ -1280,23 +1292,23 @@ static long sock_ioctl(struct file *file, unsigned cmd, unsigned long arg)
                        break;
                case SIOCGSTAMP_OLD:
                case SIOCGSTAMPNS_OLD:
-                       if (!sock->ops->gettstamp) {
+                       if (!ops->gettstamp) {
                                err = -ENOIOCTLCMD;
                                break;
                        }
-                       err = sock->ops->gettstamp(sock, argp,
-                                                  cmd == SIOCGSTAMP_OLD,
-                                                  !IS_ENABLED(CONFIG_64BIT));
+                       err = ops->gettstamp(sock, argp,
+                                            cmd == SIOCGSTAMP_OLD,
+                                            !IS_ENABLED(CONFIG_64BIT));
                        break;
                case SIOCGSTAMP_NEW:
                case SIOCGSTAMPNS_NEW:
-                       if (!sock->ops->gettstamp) {
+                       if (!ops->gettstamp) {
                                err = -ENOIOCTLCMD;
                                break;
                        }
-                       err = sock->ops->gettstamp(sock, argp,
-                                                  cmd == SIOCGSTAMP_NEW,
-                                                  false);
+                       err = ops->gettstamp(sock, argp,
+                                            cmd == SIOCGSTAMP_NEW,
+                                            false);
                        break;
 
                case SIOCGIFCONF:
@@ -1357,9 +1369,10 @@ EXPORT_SYMBOL(sock_create_lite);
 static __poll_t sock_poll(struct file *file, poll_table *wait)
 {
        struct socket *sock = file->private_data;
+       const struct proto_ops *ops = READ_ONCE(sock->ops);
        __poll_t events = poll_requested_events(wait), flag = 0;
 
-       if (!sock->ops->poll)
+       if (!ops->poll)
                return 0;
 
        if (sk_can_busy_loop(sock->sk)) {
@@ -1371,14 +1384,14 @@ static __poll_t sock_poll(struct file *file, poll_table *wait)
                flag = POLL_BUSY_LOOP;
        }
 
-       return sock->ops->poll(file, sock, wait) | flag;
+       return ops->poll(file, sock, wait) | flag;
 }
 
 static int sock_mmap(struct file *file, struct vm_area_struct *vma)
 {
        struct socket *sock = file->private_data;
 
-       return sock->ops->mmap(file, sock, vma);
+       return READ_ONCE(sock->ops)->mmap(file, sock, vma);
 }
 
 static int sock_close(struct inode *inode, struct file *filp)
@@ -1728,7 +1741,7 @@ int __sys_socketpair(int family, int type, int protocol, int __user *usockvec)
                goto out;
        }
 
-       err = sock1->ops->socketpair(sock1, sock2);
+       err = READ_ONCE(sock1->ops)->socketpair(sock1, sock2);
        if (unlikely(err < 0)) {
                sock_release(sock2);
                sock_release(sock1);
@@ -1789,7 +1802,7 @@ int __sys_bind(int fd, struct sockaddr __user *umyaddr, int addrlen)
                                                   (struct sockaddr *)&address,
                                                   addrlen);
                        if (!err)
-                               err = sock->ops->bind(sock,
+                               err = READ_ONCE(sock->ops)->bind(sock,
                                                      (struct sockaddr *)
                                                      &address, addrlen);
                }
@@ -1823,7 +1836,7 @@ int __sys_listen(int fd, int backlog)
 
                err = security_socket_listen(sock, backlog);
                if (!err)
-                       err = sock->ops->listen(sock, backlog);
+                       err = READ_ONCE(sock->ops)->listen(sock, backlog);
 
                fput_light(sock->file, fput_needed);
        }
@@ -1843,6 +1856,7 @@ struct file *do_accept(struct file *file, unsigned file_flags,
        struct file *newfile;
        int err, len;
        struct sockaddr_storage address;
+       const struct proto_ops *ops;
 
        sock = sock_from_file(file);
        if (!sock)
@@ -1851,15 +1865,16 @@ struct file *do_accept(struct file *file, unsigned file_flags,
        newsock = sock_alloc();
        if (!newsock)
                return ERR_PTR(-ENFILE);
+       ops = READ_ONCE(sock->ops);
 
        newsock->type = sock->type;
-       newsock->ops = sock->ops;
+       newsock->ops = ops;
 
        /*
         * We don't need try_module_get here, as the listening socket (sock)
         * has the protocol module (sock->ops->owner) held.
         */
-       __module_get(newsock->ops->owner);
+       __module_get(ops->owner);
 
        newfile = sock_alloc_file(newsock, flags, sock->sk->sk_prot_creator->name);
        if (IS_ERR(newfile))
@@ -1869,14 +1884,13 @@ struct file *do_accept(struct file *file, unsigned file_flags,
        if (err)
                goto out_fd;
 
-       err = sock->ops->accept(sock, newsock, sock->file->f_flags | file_flags,
+       err = ops->accept(sock, newsock, sock->file->f_flags | file_flags,
                                        false);
        if (err < 0)
                goto out_fd;
 
        if (upeer_sockaddr) {
-               len = newsock->ops->getname(newsock,
-                                       (struct sockaddr *)&address, 2);
+               len = ops->getname(newsock, (struct sockaddr *)&address, 2);
                if (len < 0) {
                        err = -ECONNABORTED;
                        goto out_fd;
@@ -1989,8 +2003,8 @@ int __sys_connect_file(struct file *file, struct sockaddr_storage *address,
        if (err)
                goto out;
 
-       err = sock->ops->connect(sock, (struct sockaddr *)address, addrlen,
-                                sock->file->f_flags | file_flags);
+       err = READ_ONCE(sock->ops)->connect(sock, (struct sockaddr *)address,
+                               addrlen, sock->file->f_flags | file_flags);
 out:
        return err;
 }
@@ -2039,7 +2053,7 @@ int __sys_getsockname(int fd, struct sockaddr __user *usockaddr,
        if (err)
                goto out_put;
 
-       err = sock->ops->getname(sock, (struct sockaddr *)&address, 0);
+       err = READ_ONCE(sock->ops)->getname(sock, (struct sockaddr *)&address, 0);
        if (err < 0)
                goto out_put;
        /* "err" is actually length in this case */
@@ -2071,13 +2085,15 @@ int __sys_getpeername(int fd, struct sockaddr __user *usockaddr,
 
        sock = sockfd_lookup_light(fd, &err, &fput_needed);
        if (sock != NULL) {
+               const struct proto_ops *ops = READ_ONCE(sock->ops);
+
                err = security_socket_getpeername(sock);
                if (err) {
                        fput_light(sock->file, fput_needed);
                        return err;
                }
 
-               err = sock->ops->getname(sock, (struct sockaddr *)&address, 1);
+               err = ops->getname(sock, (struct sockaddr *)&address, 1);
                if (err >= 0)
                        /* "err" is actually length in this case */
                        err = move_addr_to_user(&address, err, usockaddr,
@@ -2227,6 +2243,7 @@ int __sys_setsockopt(int fd, int level, int optname, char __user *user_optval,
                int optlen)
 {
        sockptr_t optval = USER_SOCKPTR(user_optval);
+       const struct proto_ops *ops;
        char *kernel_optval = NULL;
        int err, fput_needed;
        struct socket *sock;
@@ -2255,12 +2272,13 @@ int __sys_setsockopt(int fd, int level, int optname, char __user *user_optval,
 
        if (kernel_optval)
                optval = KERNEL_SOCKPTR(kernel_optval);
+       ops = READ_ONCE(sock->ops);
        if (level == SOL_SOCKET && !sock_use_custom_sol_socket(sock))
                err = sock_setsockopt(sock, level, optname, optval, optlen);
-       else if (unlikely(!sock->ops->setsockopt))
+       else if (unlikely(!ops->setsockopt))
                err = -EOPNOTSUPP;
        else
-               err = sock->ops->setsockopt(sock, level, optname, optval,
+               err = ops->setsockopt(sock, level, optname, optval,
                                            optlen);
        kfree(kernel_optval);
 out_put:
@@ -2285,6 +2303,7 @@ int __sys_getsockopt(int fd, int level, int optname, char __user *optval,
                int __user *optlen)
 {
        int max_optlen __maybe_unused;
+       const struct proto_ops *ops;
        int err, fput_needed;
        struct socket *sock;
 
@@ -2299,12 +2318,13 @@ int __sys_getsockopt(int fd, int level, int optname, char __user *optval,
        if (!in_compat_syscall())
                max_optlen = BPF_CGROUP_GETSOCKOPT_MAX_OPTLEN(optlen);
 
+       ops = READ_ONCE(sock->ops);
        if (level == SOL_SOCKET)
                err = sock_getsockopt(sock, level, optname, optval, optlen);
-       else if (unlikely(!sock->ops->getsockopt))
+       else if (unlikely(!ops->getsockopt))
                err = -EOPNOTSUPP;
        else
-               err = sock->ops->getsockopt(sock, level, optname, optval,
+               err = ops->getsockopt(sock, level, optname, optval,
                                            optlen);
 
        if (!in_compat_syscall())
@@ -2332,7 +2352,7 @@ int __sys_shutdown_sock(struct socket *sock, int how)
 
        err = security_socket_shutdown(sock, how);
        if (!err)
-               err = sock->ops->shutdown(sock, how);
+               err = READ_ONCE(sock->ops)->shutdown(sock, how);
 
        return err;
 }
@@ -3324,6 +3344,7 @@ static int compat_sock_ioctl_trans(struct file *file, struct socket *sock,
        void __user *argp = compat_ptr(arg);
        struct sock *sk = sock->sk;
        struct net *net = sock_net(sk);
+       const struct proto_ops *ops;
 
        if (cmd >= SIOCDEVPRIVATE && cmd <= (SIOCDEVPRIVATE + 15))
                return sock_ioctl(file, cmd, (unsigned long)argp);
@@ -3333,10 +3354,11 @@ static int compat_sock_ioctl_trans(struct file *file, struct socket *sock,
                return compat_siocwandev(net, argp);
        case SIOCGSTAMP_OLD:
        case SIOCGSTAMPNS_OLD:
-               if (!sock->ops->gettstamp)
+               ops = READ_ONCE(sock->ops);
+               if (!ops->gettstamp)
                        return -ENOIOCTLCMD;
-               return sock->ops->gettstamp(sock, argp, cmd == SIOCGSTAMP_OLD,
-                                           !COMPAT_USE_64BIT_TIME);
+               return ops->gettstamp(sock, argp, cmd == SIOCGSTAMP_OLD,
+                                     !COMPAT_USE_64BIT_TIME);
 
        case SIOCETHTOOL:
        case SIOCBONDSLAVEINFOQUERY:
@@ -3417,6 +3439,7 @@ static long compat_sock_ioctl(struct file *file, unsigned int cmd,
                              unsigned long arg)
 {
        struct socket *sock = file->private_data;
+       const struct proto_ops *ops = READ_ONCE(sock->ops);
        int ret = -ENOIOCTLCMD;
        struct sock *sk;
        struct net *net;
@@ -3424,8 +3447,8 @@ static long compat_sock_ioctl(struct file *file, unsigned int cmd,
        sk = sock->sk;
        net = sock_net(sk);
 
-       if (sock->ops->compat_ioctl)
-               ret = sock->ops->compat_ioctl(sock, cmd, arg);
+       if (ops->compat_ioctl)
+               ret = ops->compat_ioctl(sock, cmd, arg);
 
        if (ret == -ENOIOCTLCMD &&
            (cmd >= SIOCIWFIRST && cmd <= SIOCIWLAST))
@@ -3449,7 +3472,7 @@ static long compat_sock_ioctl(struct file *file, unsigned int cmd,
 
 int kernel_bind(struct socket *sock, struct sockaddr *addr, int addrlen)
 {
-       return sock->ops->bind(sock, addr, addrlen);
+       return READ_ONCE(sock->ops)->bind(sock, addr, addrlen);
 }
 EXPORT_SYMBOL(kernel_bind);
 
@@ -3463,7 +3486,7 @@ EXPORT_SYMBOL(kernel_bind);
 
 int kernel_listen(struct socket *sock, int backlog)
 {
-       return sock->ops->listen(sock, backlog);
+       return READ_ONCE(sock->ops)->listen(sock, backlog);
 }
 EXPORT_SYMBOL(kernel_listen);
 
@@ -3481,6 +3504,7 @@ EXPORT_SYMBOL(kernel_listen);
 int kernel_accept(struct socket *sock, struct socket **newsock, int flags)
 {
        struct sock *sk = sock->sk;
+       const struct proto_ops *ops = READ_ONCE(sock->ops);
        int err;
 
        err = sock_create_lite(sk->sk_family, sk->sk_type, sk->sk_protocol,
@@ -3488,15 +3512,15 @@ int kernel_accept(struct socket *sock, struct socket **newsock, int flags)
        if (err < 0)
                goto done;
 
-       err = sock->ops->accept(sock, *newsock, flags, true);
+       err = ops->accept(sock, *newsock, flags, true);
        if (err < 0) {
                sock_release(*newsock);
                *newsock = NULL;
                goto done;
        }
 
-       (*newsock)->ops = sock->ops;
-       __module_get((*newsock)->ops->owner);
+       (*newsock)->ops = ops;
+       __module_get(ops->owner);
 
 done:
        return err;
@@ -3519,7 +3543,7 @@ EXPORT_SYMBOL(kernel_accept);
 int kernel_connect(struct socket *sock, struct sockaddr *addr, int addrlen,
                   int flags)
 {
-       return sock->ops->connect(sock, addr, addrlen, flags);
+       return READ_ONCE(sock->ops)->connect(sock, addr, addrlen, flags);
 }
 EXPORT_SYMBOL(kernel_connect);
 
@@ -3534,7 +3558,7 @@ EXPORT_SYMBOL(kernel_connect);
 
 int kernel_getsockname(struct socket *sock, struct sockaddr *addr)
 {
-       return sock->ops->getname(sock, addr, 0);
+       return READ_ONCE(sock->ops)->getname(sock, addr, 0);
 }
 EXPORT_SYMBOL(kernel_getsockname);
 
@@ -3549,7 +3573,7 @@ EXPORT_SYMBOL(kernel_getsockname);
 
 int kernel_getpeername(struct socket *sock, struct sockaddr *addr)
 {
-       return sock->ops->getname(sock, addr, 1);
+       return READ_ONCE(sock->ops)->getname(sock, addr, 1);
 }
 EXPORT_SYMBOL(kernel_getpeername);
 
@@ -3563,7 +3587,7 @@ EXPORT_SYMBOL(kernel_getpeername);
 
 int kernel_sock_shutdown(struct socket *sock, enum sock_shutdown_cmd how)
 {
-       return sock->ops->shutdown(sock, how);
+       return READ_ONCE(sock->ops)->shutdown(sock, how);
 }
 EXPORT_SYMBOL(kernel_sock_shutdown);
 

diff --git a/net/unix/scm.c b/net/unix/scm.c
index f915288..e9dde71 100644 (file)
--- a/net/unix/scm.c
+++ b/net/unix/scm.c
@@ -29,10 +29,11 @@ struct sock *unix_get_socket(struct file *filp)
        /* Socket ? */
        if (S_ISSOCK(inode->i_mode) && !(filp->f_mode & FMODE_PATH)) {
                struct socket *sock = SOCKET_I(inode);
+               const struct proto_ops *ops = READ_ONCE(sock->ops);
                struct sock *s = sock->sk;
 
                /* PF_UNIX ? */
-               if (s && sock->ops && sock->ops->family == PF_UNIX)
+               if (s && ops && ops->family == PF_UNIX)
                        u_sock = s;
        } else {
                /* Could be an io_uring instance */