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.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(-)

diff --git a/lib/http.c b/lib/http.c

index 1a313b4fb..e080ae513 100644

--- a/lib/http.c

+++ b/lib/http.c

@@ -3012,10 +3012,12 @@ CURLcode Curl_http_readwrite_headers(struct Curl_easy *data,

ssize_t *nread,

bool *stop_reading)

{

CURLcode result;

struct SingleRequest *k = &data->req;

+ ssize_t onread = *nread;

+ char *ostr = k->str;

/* header line within buffer loop */

do {

size_t rest_length;

size_t full_length;

@@ -3076,11 +3078,13 @@ CURLcode Curl_http_readwrite_headers(struct Curl_easy *data,

/* since there's more, this is a partial bad header */

k->badheader = HEADER_PARTHEADER;

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;

}

}

--

2.17.0