From 5da028a8af38eced330332d5ae51c212e9e86242 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Tue, 27 Jun 2017 18:24:21 -0400 Subject: [PATCH] get_compat_msghdr(): get rid of field-by-field copyin Signed-off-by: Al Viro --- net/compat.c | 31 ++++++++++++++----------------- 1 file changed, 14 insertions(+), 17 deletions(-) diff --git a/net/compat.c b/net/compat.c index aba929e5250f..dba5e222a0e5 100644 --- a/net/compat.c +++ b/net/compat.c @@ -37,21 +37,16 @@ int get_compat_msghdr(struct msghdr *kmsg, struct sockaddr __user **save_addr, struct iovec **iov) { - compat_uptr_t uaddr, uiov, tmp3; - compat_size_t nr_segs; + struct compat_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(tmp3, &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_flags = msg.msg_flags; + kmsg->msg_namelen = msg.msg_namelen; + + if (!msg.msg_name) kmsg->msg_namelen = 0; if (kmsg->msg_namelen < 0) @@ -59,14 +54,16 @@ int get_compat_msghdr(struct msghdr *kmsg, if (kmsg->msg_namelen > sizeof(struct sockaddr_storage)) kmsg->msg_namelen = sizeof(struct sockaddr_storage); - kmsg->msg_control = compat_ptr(tmp3); + + kmsg->msg_control = compat_ptr(msg.msg_control); + kmsg->msg_controllen = msg.msg_controllen; if (save_addr) - *save_addr = compat_ptr(uaddr); + *save_addr = compat_ptr(msg.msg_name); - if (uaddr && kmsg->msg_namelen) { + if (msg.msg_name && kmsg->msg_namelen) { if (!save_addr) { - err = move_addr_to_kernel(compat_ptr(uaddr), + err = move_addr_to_kernel(compat_ptr(msg.msg_name), kmsg->msg_namelen, kmsg->msg_name); if (err < 0) @@ -77,13 +74,13 @@ int get_compat_msghdr(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 compat_import_iovec(save_addr ? READ : WRITE, - compat_ptr(uiov), nr_segs, + compat_ptr(msg.msg_iov), msg.msg_iovlen, UIO_FASTIOV, iov, &kmsg->msg_iter); } -- 2.20.1