From 490e7c87e0378fb22eadfcc0c6d933db04206ae9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Joakim=20Nohlg=C3=A5rd?= <joakim.nohlgard@eistec.se>
Date: Mon, 12 Feb 2018 08:45:19 +0100
Subject: [PATCH] sys/vfs: Check suggested fd is valid

Avoids out of bounds array access on _vfs_open_files if vfs_bind is
called with an invalid (positive) fd number
---
 sys/vfs/vfs.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/sys/vfs/vfs.c b/sys/vfs/vfs.c
index 37db7479ef..9eb4c1d309 100644
--- a/sys/vfs/vfs.c
+++ b/sys/vfs/vfs.c
@@ -871,10 +871,10 @@ static inline int _allocate_fd(int fd)
                 break;
             }
         }
-        if (fd >= VFS_MAX_OPEN_FILES) {
-            /* The _vfs_open_files array is full */
-            return -ENFILE;
-        }
+    }
+    if (fd >= VFS_MAX_OPEN_FILES) {
+        /* The _vfs_open_files array is full */
+        return -ENFILE;
     }
     else if (_vfs_open_files[fd].pid != KERNEL_PID_UNDEF) {
         /* The desired fd is already in use */