From d30858296331b3ab1dc57043eef66fddf87637c3 Mon Sep 17 00:00:00 2001
From: Daniel Stenberg <daniel@haxx.se>
Date: Tue, 1 Aug 2017 17:16:46 +0200
Subject: [PATCH] tftp: reject file name lengths that don't fit
... and thereby avoid telling send() to send off more bytes than the
size of the buffer!
CVE-2017-1000100
Bug: https://curl.haxx.se/docs/adv_20170809B.html
Reported-by: Even Rouault
Credit to OSS-Fuzz for the discovery
Upstream-commit: 358b2b131ad6c095696f20dcfa62b8305263f898
Signed-off-by: Kamil Dudka <kdudka@redhat.com>
---
lib/tftp.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/lib/tftp.c b/lib/tftp.c
index f2f8347..92b3edf 100644
--- a/lib/tftp.c
+++ b/lib/tftp.c
@@ -5,7 +5,7 @@
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
- * Copyright (C) 1998 - 2016, Daniel Stenberg, <daniel@haxx.se>, et al.
+ * Copyright (C) 1998 - 2017, Daniel Stenberg, <daniel@haxx.se>, et al.
*
* This software is licensed as described in the file COPYING, which
* you should have received as part of this distribution. The terms
@@ -490,6 +490,11 @@ static CURLcode tftp_send_first(tftp_state_data_t *state, tftp_event_t event)
if(result)
return result;
+ if(strlen(filename) > (state->blksize - strlen(mode) - 4)) {
+ failf(data, "TFTP file name too long\n");
+ return CURLE_TFTP_ILLEGAL; /* too long file name field */
+ }
+
snprintf((char *)state->spacket.data+2,
state->blksize,
"%s%c%s%c", filename, '\0', mode, '\0');
--
2.9.4