From 8c7b3737d29ed5c0575bf592063de8a51450812d Mon Sep 17 00:00:00 2001
From: Daniel Stenberg <daniel@haxx.se>
Date: Sat, 24 Mar 2018 23:47:41 +0100
Subject: [PATCH] http: restore buffer pointer when bad response-line is parsed

... leaving the k->str could lead to buffer over-reads later on.

CVE: CVE-2018-1000301
Assisted-by: Max Dymond

Detected by OSS-Fuzz.
Bug: https://curl.haxx.se/docs/adv_2018-b138.html
Bug: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=7105
---
 lib/http.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

--- a/lib/http.c
+++ b/lib/http.c
@@ -2924,6 +2924,8 @@ CURLcode Curl_http_readwrite_headers(str
 {
   CURLcode result;
   struct SingleRequest *k = &data->req;
+  ssize_t onread = *nread;
+  char *ostr = k->str;
 
   /* header line within buffer loop */
   do {
@@ -2988,7 +2990,9 @@ CURLcode Curl_http_readwrite_headers(str
         else {
           /* this was all we read so it's all a bad header */
           k->badheader = HEADER_ALLBAD;
-          *nread = (ssize_t)rest_length;
+          *nread = onread;
+          k->str = ostr;
+          return CURLE_OK;
         }
         break;
       }