[nginx] Core: fix misallocation at ngx_crypt_apr1 (ticket #412).

[Maxim Dounin]

details:   http://hg.nginx.org/nginx/rev/6961d52ebc49
branches:  stable-1.4
changeset: 5418:6961d52ebc49
user:      Markus Linnala <Markus.Linnala at cybercom.com>
date:      Fri Sep 20 17:57:21 2013 +0300
description:
Core: fix misallocation at ngx_crypt_apr1 (ticket #412).

Found by using auth_basic.t from mdounin nginx-tests under valgrind.

==10470== Invalid write of size 1
==10470==    at 0x43603D: ngx_crypt_to64 (ngx_crypt.c:168)
==10470==    by 0x43648E: ngx_crypt (ngx_crypt.c:153)
==10470==    by 0x489D8B: ngx_http_auth_basic_crypt_handler (ngx_http_auth_basic_module.c:297)
==10470==    by 0x48A24A: ngx_http_auth_basic_handler (ngx_http_auth_basic_module.c:240)
==10470==    by 0x44EAB9: ngx_http_core_access_phase (ngx_http_core_module.c:1121)
==10470==    by 0x44A822: ngx_http_core_run_phases (ngx_http_core_module.c:895)
==10470==    by 0x44A932: ngx_http_handler (ngx_http_core_module.c:878)
==10470==    by 0x455EEF: ngx_http_process_request (ngx_http_request.c:1852)
==10470==    by 0x456527: ngx_http_process_request_headers (ngx_http_request.c:1283)
==10470==    by 0x456A91: ngx_http_process_request_line (ngx_http_request.c:964)
==10470==    by 0x457097: ngx_http_wait_request_handler (ngx_http_request.c:486)
==10470==    by 0x4411EE: ngx_epoll_process_events (ngx_epoll_module.c:691)
==10470==  Address 0x5866fab is 0 bytes after a block of size 27 alloc'd
==10470==    at 0x4A074CD: malloc (vg_replace_malloc.c:236)
==10470==    by 0x43B251: ngx_alloc (ngx_alloc.c:22)
==10470==    by 0x421B0D: ngx_malloc (ngx_palloc.c:119)
==10470==    by 0x421B65: ngx_pnalloc (ngx_palloc.c:147)
==10470==    by 0x436368: ngx_crypt (ngx_crypt.c:140)
==10470==    by 0x489D8B: ngx_http_auth_basic_crypt_handler (ngx_http_auth_basic_module.c:297)
==10470==    by 0x48A24A: ngx_http_auth_basic_handler (ngx_http_auth_basic_module.c:240)
==10470==    by 0x44EAB9: ngx_http_core_access_phase (ngx_http_core_module.c:1121)
==10470==    by 0x44A822: ngx_http_core_run_phases (ngx_http_core_module.c:895)
==10470==    by 0x44A932: ngx_http_handler (ngx_http_core_module.c:878)
==10470==    by 0x455EEF: ngx_http_process_request (ngx_http_request.c:1852)
==10470==    by 0x456527: ngx_http_process_request_headers (ngx_http_request.c:1283)
==10470==

diffstat:

 src/core/ngx_crypt.c |  2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diffs (12 lines):

diff --git a/src/core/ngx_crypt.c b/src/core/ngx_crypt.c
--- a/src/core/ngx_crypt.c
+++ b/src/core/ngx_crypt.c
@@ -137,7 +137,7 @@ ngx_crypt_apr1(ngx_pool_t *pool, u_char 
 
     /* output */
 
-    *encrypted = ngx_pnalloc(pool, sizeof("$apr1$") - 1 + saltlen + 16 + 1);
+    *encrypted = ngx_pnalloc(pool, sizeof("$apr1$") - 1 + saltlen + 1 + 22 + 1);
     if (*encrypted == NULL) {
         return NGX_ERROR;
     }