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, 5 deletions

diff --git a/src/nvim/vim.h b/src/nvim/vim.h
index 29d61dcbde..410c2602c8 100644
--- a/src/nvim/vim.h
+++ b/src/nvim/vim.h
@@ -322,13 +322,10 @@ enum {
     (size_t)(n))
 
 #ifndef EINTR
-# define read_eintr(fd, buf, count) vim_read((fd), (buf), (count))
-# define write_eintr(fd, buf, count) vim_write((fd), (buf), (count))
+# define read_eintr(fd, buf, count) read((fd), (buf), (count))
+# define write_eintr(fd, buf, count) write((fd), (buf), (count))
 #endif
 
-# define vim_read(fd, buf, count)   read((fd), (char *)(buf), (size_t) (count))
-# define vim_write(fd, buf, count)  write((fd), (char *)(buf), (size_t) (count))
-
 /*
  * Enums need a typecast to be used as array index (for Ultrix).
  */