From ffb07550c76f70b8fa5e57352e7e299f4811f0a0 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Tue, 27 Jun 2017 19:32:04 -0400 Subject: [PATCH] copy_msghdr_from_user(): get rid of field-by-field copyin Signed-off-by: Al Viro --- net/socket.c | 31 ++++++++++++++----------------- 1 file changed, 14 insertions(+), 17 deletions(-) diff --git a/net/socket.c b/net/socket.c index c2564eb25c6b..af33d929135a 100644 --- a/net/socket.c +++ b/net/socket.c @@ -1870,22 +1870,18 @@ static int copy_msghdr_from_user(struct msghdr *kmsg, struct sockaddr __user **save_addr, struct iovec **iov) { - struct sockaddr __user *uaddr; - struct iovec __user *uiov; - size_t nr_segs; + struct user_msghdr msg; ssize_t err; - if (!access_ok(VERIFY_READ, umsg, sizeof(*umsg)) || - __get_user(uaddr, &umsg->msg_name) || - __get_user(kmsg->msg_namelen, &umsg->msg_namelen) || - __get_user(uiov, &umsg->msg_iov) || - __get_user(nr_segs, &umsg->msg_iovlen) || - __get_user(kmsg->msg_control, &umsg->msg_control) || - __get_user(kmsg->msg_controllen, &umsg->msg_controllen) || - __get_user(kmsg->msg_flags, &umsg->msg_flags)) + if (copy_from_user(&msg, umsg, sizeof(*umsg))) return -EFAULT; - if (!uaddr) + kmsg->msg_control = msg.msg_control; + kmsg->msg_controllen = msg.msg_controllen; + kmsg->msg_flags = msg.msg_flags; + + kmsg->msg_namelen = msg.msg_namelen; + if (!msg.msg_name) kmsg->msg_namelen = 0; if (kmsg->msg_namelen < 0) @@ -1895,11 +1891,11 @@ static int copy_msghdr_from_user(struct msghdr *kmsg, kmsg->msg_namelen = sizeof(struct sockaddr_storage); if (save_addr) - *save_addr = uaddr; + *save_addr = msg.msg_name; - if (uaddr && kmsg->msg_namelen) { + if (msg.msg_name && kmsg->msg_namelen) { if (!save_addr) { - err = move_addr_to_kernel(uaddr, kmsg->msg_namelen, + err = move_addr_to_kernel(msg.msg_name, kmsg->msg_namelen, kmsg->msg_name); if (err < 0) return err; @@ -1909,12 +1905,13 @@ static int copy_msghdr_from_user(struct msghdr *kmsg, kmsg->msg_namelen = 0; } - if (nr_segs > UIO_MAXIOV) + if (msg.msg_iovlen > UIO_MAXIOV) return -EMSGSIZE; kmsg->msg_iocb = NULL; - return import_iovec(save_addr ? READ : WRITE, uiov, nr_segs, + return import_iovec(save_addr ? READ : WRITE, + msg.msg_iov, msg.msg_iovlen, UIO_FASTIOV, iov, &kmsg->msg_iter); } -- 2.20.1