From 05da7fb51cda374ae351829f67018924f931f18b Mon Sep 17 00:00:00 2001 From: Sergio Correia 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 #include +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