[Bug stdio/19165] fread overflow

["ppluzhnikov at google dot com" <sourceware-bugzilla at sourceware dot org>]

https://sourceware.org/bugzilla/show_bug.cgi?id=19165

Paul Pluzhnikov <ppluzhnikov at google dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |ppluzhnikov at google dot com

--- Comment #5 from Paul Pluzhnikov <ppluzhnikov at google dot com> ---
The following patch seems like it's both more efficient *and* provides correct
answer:

diff --git a/libio/iofread.c b/libio/iofread.c
index eb69b05..a8ea391 100644
--- a/libio/iofread.c
+++ b/libio/iofread.c
@@ -37,7 +37,7 @@ _IO_fread (void *buf, _IO_size_t size, _IO_size_t count,
_IO_FILE *fp)
   _IO_acquire_lock (fp);
   bytes_read = _IO_sgetn (fp, (char *) buf, bytes_requested);
   _IO_release_lock (fp);
-  return bytes_requested == bytes_read ? count : bytes_read / size;
+  return bytes_read / size;
 }
 libc_hidden_def (_IO_fread)

diff --git a/libio/iofread_u.c b/libio/iofread_u.c
index 997b714..28651bf 100644
--- a/libio/iofread_u.c
+++ b/libio/iofread_u.c
@@ -38,7 +38,7 @@ __fread_unlocked (void *buf, _IO_size_t size, _IO_size_t
count, _IO_FILE *fp)
   if (bytes_requested == 0)
     return 0;
   bytes_read = _IO_sgetn (fp, (char *) buf, bytes_requested);
-  return bytes_requested == bytes_read ? count : bytes_read / size;
+  return bytes_read / size;
 }
 libc_hidden_def (__fread_unlocked)
 weak_alias (__fread_unlocked, fread_unlocked)



The fwrite case is slightly more complicated by EOF being an indication that
"all bytes were written".

I'll mail a patch to libc-alpha...

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