net: switch sendto() and recvfrom() to import_single_range()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 8 insertions, 16 deletions

diff --git a/net/socket.c b/net/socket.c
index 989b1ae32afa..46f0e1d752b3 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -1650,18 +1650,14 @@ SYSCALL_DEFINE6(sendto, int, fd, void __user *, buff, size_t, len,
         struct iovec iov;
         int fput_needed;
 
-        if (len > INT_MAX)
-                len = INT_MAX;
-        if (unlikely(!access_ok(VERIFY_READ, buff, len)))
-                return -EFAULT;
+        err = import_single_range(WRITE, buff, len, &iov, &msg.msg_iter);
+        if (unlikely(err))
+                return err;
         sock = sockfd_lookup_light(fd, &err, &fput_needed);
         if (!sock)
                 goto out;
 
-        iov.iov_base = buff;
-        iov.iov_len = len;
         msg.msg_name = NULL;
-        iov_iter_init(&msg.msg_iter, WRITE, &iov, 1, len);
         msg.msg_control = NULL;
         msg.msg_controllen = 0;
         msg.msg_namelen = 0;
@@ -1675,7 +1671,7 @@ SYSCALL_DEFINE6(sendto, int, fd, void __user *, buff, size_t, len,
         if (sock->file->f_flags & O_NONBLOCK)
                 flags |= MSG_DONTWAIT;
         msg.msg_flags = flags;
-        err = sock_sendmsg(sock, &msg, len);
+        err = sock_sendmsg(sock, &msg, iov_iter_count(&msg.msg_iter));
 
 out_put:
         fput_light(sock->file, fput_needed);
@@ -1710,26 +1706,22 @@ SYSCALL_DEFINE6(recvfrom, int, fd, void __user *, ubuf, size_t, size,
         int err, err2;
         int fput_needed;
 
-        if (size > INT_MAX)
-                size = INT_MAX;
-        if (unlikely(!access_ok(VERIFY_WRITE, ubuf, size)))
-                return -EFAULT;
+        err = import_single_range(READ, ubuf, size, &iov, &msg.msg_iter);
+        if (unlikely(err))
+                return err;
         sock = sockfd_lookup_light(fd, &err, &fput_needed);
         if (!sock)
                 goto out;
 
         msg.msg_control = NULL;
         msg.msg_controllen = 0;
-        iov.iov_len = size;
-        iov.iov_base = ubuf;
-        iov_iter_init(&msg.msg_iter, READ, &iov, 1, size);
         /* Save some cycles and don't copy the address if not needed */
         msg.msg_name = addr ? (struct sockaddr *)&address : NULL;
         /* We assume all kernel code knows the size of sockaddr_storage */
         msg.msg_namelen = 0;
         if (sock->file->f_flags & O_NONBLOCK)
                 flags |= MSG_DONTWAIT;
-        err = sock_recvmsg(sock, &msg, size, flags);
+        err = sock_recvmsg(sock, &msg, iov_iter_count(&msg.msg_iter), flags);
 
         if (err >= 0 && addr != NULL) {
                 err2 = move_addr_to_user(&address,