From 29b251362e1839d7094993edbed8f9467069773f Mon Sep 17 00:00:00 2001
From: Daniel Stenberg <daniel@haxx.se>
Date: Mon, 25 Sep 2017 00:35:22 +0200
Subject: [PATCH] FTP: zero terminate the entry path even on bad input

... a single double quote could leave the entry path buffer without a zero
terminating byte. CVE-2017-1000254

Test 1152 added to verify.

Reported-by: Max Dymond
Bug: https://curl.haxx.se/docs/adv_20171004.html
---
 lib/ftp.c               |  7 ++++--
 3 files changed, 67 insertions(+), 2 deletions(-)
 create mode 100644 tests/data/test1152

diff --git a/lib/ftp.c b/lib/ftp.c
index 4860509f3..54ba4057f 100644
--- a/lib/ftp.c
+++ b/lib/ftp.c
@@ -2777,10 +2777,11 @@ static CURLcode ftp_statemach_act(struct connectdata *conn)
       if(ftpcode == 257) {
         char *ptr = &data->state.buffer[4];  /* start on the first letter */
         const size_t buf_size = data->set.buffer_size;
         char *dir;
         char *store;
+        bool entry_extracted = FALSE;
 
         dir = malloc(nread + 1);
         if(!dir)
           return CURLE_OUT_OF_MEMORY;
 
@@ -2808,20 +2809,22 @@ static CURLcode ftp_statemach_act(struct connectdata *conn)
                 *store = ptr[1];
                 ptr++;
               }
               else {
                 /* end of path */
-                *store = '\0'; /* zero terminate */
+                entry_extracted = TRUE;
                 break; /* get out of this loop */
               }
             }
             else
               *store = *ptr;
             store++;
             ptr++;
           }
-
+          *store = '\0'; /* zero terminate */
+        }
+        if(entry_extracted) {
           /* If the path name does not look like an absolute path (i.e.: it
              does not start with a '/'), we probably need some server-dependent
              adjustments. For example, this is the case when connecting to
              an OS400 FTP server: this server supports two name syntaxes,
              the default one being incompatible with standard paths. In