From 05da7fb51cda374ae351829f67018924f931f18b Mon Sep 17 00:00:00 2001

From: Sergio Correia <scorreia@redhat.com>

Date: Tue, 18 Feb 2020 09:10:18 -0300

Subject: [PATCH] CVE-2018-12121

---

 http_parser.c | 15 +++++++++++----

 http_parser.h |  3 +++

 2 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/http_parser.c b/http_parser.c

index f9991c3..aef4437 100644

--- a/http_parser.c

+++ b/http_parser.c

@@ -25,6 +25,8 @@

 #include <string.h>

 #include <limits.h>

+static uint32_t max_header_size = HTTP_MAX_HEADER_SIZE;

+

 #ifndef ULLONG_MAX

 # define ULLONG_MAX ((uint64_t) -1) /* 2^64-1 */

 #endif

@@ -137,20 +139,20 @@ do {                                                                 \

 } while (0)

 /* Don't allow the total size of the HTTP headers (including the status

- * line) to exceed HTTP_MAX_HEADER_SIZE.  This check is here to protect

+ * line) to exceed max_header_size.  This check is here to protect

  * embedders against denial-of-service attacks where the attacker feeds

  * us a never-ending header that the embedder keeps buffering.

  *

  * This check is arguably the responsibility of embedders but we're doing

  * it on the embedder's behalf because most won't bother and this way we

- * make the web a little safer.  HTTP_MAX_HEADER_SIZE is still far bigger

+ * make the web a little safer.  max_header_size is still far bigger

  * than any reasonable request or response so this should never affect

  * day-to-day operation.

  */

 #define COUNT_HEADER_SIZE(V)                                         \

 do {                                                                 \

   parser->nread += (V);                                              \

-  if (UNLIKELY(parser->nread > (HTTP_MAX_HEADER_SIZE))) {            \

+  if (UNLIKELY(parser->nread > (max_header_size))) {                 \

     SET_ERRNO(HPE_HEADER_OVERFLOW);                                  \

     goto error;                                                      \

   }                                                                  \

@@ -1471,7 +1473,7 @@ reexecute:

               const char* p_lf;

               size_t limit = data + len - p;

-              limit = MIN(limit, HTTP_MAX_HEADER_SIZE);

+              limit = MIN(limit, max_header_size);

               p_cr = (const char*) memchr(p, CR, limit);

               p_lf = (const char*) memchr(p, LF, limit);

@@ -2438,3 +2440,8 @@ http_parser_version(void) {

          HTTP_PARSER_VERSION_MINOR * 0x00100 |

          HTTP_PARSER_VERSION_PATCH * 0x00001;

 }

+

+void

+http_parser_set_max_header_size(uint32_t size) {

+  max_header_size = size;

+}

diff --git a/http_parser.h b/http_parser.h

index 1fbf30e..ea7bafe 100644

--- a/http_parser.h

+++ b/http_parser.h

@@ -427,6 +427,9 @@ void http_parser_pause(http_parser *parser, int paused);

 /* Checks if this is the final chunk of the body. */

 int http_body_is_final(const http_parser *parser);

+/* Change the maximum header size provided at compile time. */

+void http_parser_set_max_header_size(uint32_t size);

+

 #ifdef __cplusplus

 }

 #endif

-- 

2.18.2