2 files changed, 7 insertions, 6 deletions
diff --git a/src/sys/socket/addr.rs b/src/sys/socket/addr.rs
index 1f7f4ec6..71b2c973 100644
--- a/src/sys/socket/addr.rs
+++ b/src/sys/socket/addr.rs
@@ -1,6 +1,7 @@
 use super::sa_family_t;
 use crate::{Error, Result, NixPath};
 use crate::errno::Errno;
+use memoffset::offset_of;
 use std::{fmt, mem, net, ptr, slice};
 use std::ffi::OsStr;
 use std::hash::{Hash, Hasher};
diff --git a/src/sys/socket/mod.rs b/src/sys/socket/mod.rs
index 6e22274c..c04af50f 100644
--- a/src/sys/socket/mod.rs
+++ b/src/sys/socket/mod.rs
@@ -5,6 +5,7 @@ use cfg_if::cfg_if;
 use crate::{Error, Result, errno::Errno};
 use libc::{self, c_void, c_int, iovec, socklen_t, size_t,
         CMSG_FIRSTHDR, CMSG_NXTHDR, CMSG_DATA, CMSG_LEN};
+use memoffset::offset_of;
 use std::{mem, ptr, slice};
 use std::os::unix::io::RawFd;
 #[cfg(all(target_os = "linux"))]
@@ -1113,23 +1114,22 @@ pub fn sendmmsg<'a, I, C>(
 
     let mut output = Vec::<libc::mmsghdr>::with_capacity(reserve_items);
 
-    let mut cmsgs_buffer = vec![0u8; 0];
+    let mut cmsgs_buffers = Vec::<Vec<u8>>::with_capacity(reserve_items);
 
     for d in iter {
-        let cmsgs_start = cmsgs_buffer.len();
-        let cmsgs_required_capacity: usize = d.cmsgs.as_ref().iter().map(|c| c.space()).sum();
-        let cmsgs_buffer_need_capacity = cmsgs_start + cmsgs_required_capacity;
-        cmsgs_buffer.resize(cmsgs_buffer_need_capacity, 0);
+        let capacity: usize = d.cmsgs.as_ref().iter().map(|c| c.space()).sum();
+        let mut cmsgs_buffer = vec![0u8; capacity];
 
         output.push(libc::mmsghdr {
             msg_hdr: pack_mhdr_to_send(
-                &mut cmsgs_buffer[cmsgs_start..],
+                &mut cmsgs_buffer,
                 &d.iov,
                 &d.cmsgs,
                 d.addr.as_ref()
             ),
             msg_len: 0,
         });
+        cmsgs_buffers.push(cmsgs_buffer);
     };
 
     let ret = unsafe { libc::sendmmsg(fd, output.as_mut_ptr(), output.len() as _, flags.bits() as _) };