coverity/13777: String not null terminated: RI.

Problem    : String not null terminated @ 1543.
Diagnostic : Real issue.
Rationale  : We are reading a struct block0, which contains some string
             fields, from a file, without checking for string fields to
             be correctly terminated. That could cause a buffer overrun
             if file has somehow been garbled.
Resolution : Add string fields check for nul termination.
             Mark issue as intentional (there seems to be no way of
             teaching coverity about read_eintr being ok that way).

Helped-by: oni-link <knil.ino@gmail.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/src/nvim/fileio.c b/src/nvim/fileio.c
index 9d4c990f3a..799a6a2a50 100644
--- a/src/nvim/fileio.c
+++ b/src/nvim/fileio.c
@@ -7416,7 +7416,7 @@ long read_eintr(int fd, void *buf, size_t bufsize)
   long ret;
 
   for (;; ) {
-    ret = vim_read(fd, buf, bufsize);
+    ret = read(fd, buf, bufsize);
     if (ret >= 0 || errno != EINTR)
       break;
   }
@@ -7435,7 +7435,7 @@ long write_eintr(int fd, void *buf, size_t bufsize)
   /* Repeat the write() so long it didn't fail, other than being interrupted
    * by a signal. */
   while (ret < (long)bufsize) {
-    wlen = vim_write(fd, (char *)buf + ret, bufsize - ret);
+    wlen = write(fd, (char *)buf + ret, bufsize - ret);
     if (wlen < 0) {
       if (errno != EINTR)
         break;