[tor-commits] [tor/master] Check and cast st_size to size_t in storagedir code

[nickm at torproject.org]

commit 1d617e3ed0a6c380d1bde9654a518c8a83d21db3
Author: Nick Mathewson <nickm at torproject.org>
Date:   Mon Mar 27 10:40:15 2017 +0200

    Check and cast st_size to size_t in storagedir code
    
    This prevents an i386 compilation warning and fixes bug 21828. Bug not
    in any released Tor.
---
 src/common/storagedir.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/common/storagedir.c b/src/common/storagedir.c
index b7d43dd..e28a66f 100644
--- a/src/common/storagedir.c
+++ b/src/common/storagedir.c
@@ -205,8 +205,11 @@ storage_dir_read(storage_dir_t *d, const char *fname, int bin, size_t *sz_out)
   tor_asprintf(&path, "%s/%s", d->directory, fname);
   struct stat st;
   char *contents = read_file_to_str(path, flags, &st);
-  if (contents && sz_out)
-    *sz_out = st.st_size;
+  if (contents && sz_out) {
+    // it fits in RAM, so we know its size is less than SIZE_MAX
+    tor_assert((uint64_t)st.st_size <= SIZE_MAX);
+    *sz_out = (size_t) st.st_size;
+  }
 
   tor_free(path);
   return (uint8_t *) contents;