diff --git a/net/socket.c b/net/socket.c index ade2ff5845a0..a25e513cf0f4 100644 --- a/net/socket.c +++ b/net/socket.c @@ -77,6 +77,7 @@ #include #include #include +#include #include #include #include @@ -2349,11 +2350,45 @@ SYSCALL_DEFINE5(setsockopt, int, fd, int, level, int, optname, INDIRECT_CALLABLE_DECLARE(bool tcp_bpf_bypass_getsockopt(int level, int optname)); +/* + * Initialize a sockopt_t from sockptr optval/optlen, setting up iov_iter + * for both input and output directions. + * It is important to remember that both iov points to the same data, but, + * .iter_in is read-only and .iter_out is write-only by the protocol callbacks + */ +static int sockptr_to_sockopt(sockopt_t *opt, sockptr_t optval, + sockptr_t optlen, struct kvec *kvec) +{ + int koptlen; + + if (copy_from_sockptr(&koptlen, optlen, sizeof(int))) + return -EFAULT; + + if (koptlen < 0) + return -EINVAL; + + if (optval.is_kernel) { + kvec->iov_base = optval.kernel; + kvec->iov_len = koptlen; + iov_iter_kvec(&opt->iter_out, ITER_DEST, kvec, 1, koptlen); + iov_iter_kvec(&opt->iter_in, ITER_SOURCE, kvec, 1, koptlen); + } else { + iov_iter_ubuf(&opt->iter_out, ITER_DEST, optval.user, koptlen); + iov_iter_ubuf(&opt->iter_in, ITER_SOURCE, optval.user, + koptlen); + } + opt->optlen = koptlen; + + return 0; +} + int do_sock_getsockopt(struct socket *sock, bool compat, int level, int optname, sockptr_t optval, sockptr_t optlen) { int max_optlen __maybe_unused = 0; const struct proto_ops *ops; + struct kvec kvec; + sockopt_t opt; int err; err = security_socket_getsockopt(sock, level, optname); @@ -2366,15 +2401,28 @@ int do_sock_getsockopt(struct socket *sock, bool compat, int level, ops = READ_ONCE(sock->ops); if (level == SOL_SOCKET) { err = sk_getsockopt(sock->sk, level, optname, optval, optlen); - } else if (unlikely(!ops->getsockopt)) { - err = -EOPNOTSUPP; - } else { + } else if (ops->getsockopt_iter) { + err = sockptr_to_sockopt(&opt, optval, optlen, &kvec); + if (err) + return err; + + err = ops->getsockopt_iter(sock, level, optname, &opt); + + /* Always write back optlen, even on failure. Some protocols + * (e.g. CAN raw) return -ERANGE and set optlen to the + * required buffer size so userspace can discover it. + */ + if (copy_to_sockptr(optlen, &opt.optlen, sizeof(int))) + return -EFAULT; + } else if (ops->getsockopt) { if (WARN_ONCE(optval.is_kernel || optlen.is_kernel, "Invalid argument type")) return -EOPNOTSUPP; err = ops->getsockopt(sock, level, optname, optval.user, optlen.user); + } else { + err = -EOPNOTSUPP; } if (!compat)