[PATCH 08/12] nfs: fix hypothetical use after free

[dnietoc]

From: Diego Nieto Cid <dnie...@gmail.com>

    ../../nfs/ops.c: In function 'fetch_directory':
    ../../nfs/ops.c:1962:35: warning: pointer 'buf' may be used after 'realloc' 
[-Wuse-after-free]
     1962 |                 bp = newbuf + (bp - buf);
          |                               ~~~~^~~~~~
    ../../nfs/ops.c:1959:24: note: call to 'realloc' here
     1959 |               newbuf = realloc (buf, bufmalloced *= 2);
          |                        ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
---
 nfs/ops.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/nfs/ops.c b/nfs/ops.c
index 55ff111d..95e8b11c 100644
--- a/nfs/ops.c
+++ b/nfs/ops.c
@@ -1955,11 +1955,12 @@ fetch_directory (struct iouser *cred, struct node *dir,
          if (bp + reclen > buf + bufmalloced)
            {
              char *newbuf;
+             size_t current_size = bp - buf;
 
              newbuf = realloc (buf, bufmalloced *= 2);
              assert_backtrace (newbuf);
              if (newbuf != buf)
-               bp = newbuf + (bp - buf);
+               bp = newbuf + current_size;
              buf = newbuf;
            }
 
-- 
2.51.0