[nginx] SSL: improved validation of ssl_session_cache and ssl_ocsp_cache.

[Sergey Kandaurov]

details:   https://hg.nginx.org/nginx/rev/e32b48848add
branches:  
changeset: 8088:e32b48848add
user:      Sergey Kandaurov <pluknet at nginx.com>
date:      Mon Oct 17 16:24:53 2022 +0400
description:
SSL: improved validation of ssl_session_cache and ssl_ocsp_cache.

Now it properly detects invalid shared zone configuration with omitted size.
Previously it used to read outside of the buffer boundary.

Found with AddressSanitizer.

diffstat:

 src/http/modules/ngx_http_ssl_module.c |  4 ++--
 src/mail/ngx_mail_ssl_module.c         |  2 +-
 src/stream/ngx_stream_ssl_module.c     |  2 +-
 3 files changed, 4 insertions(+), 4 deletions(-)

diffs (45 lines):

diff -r 81b4326daac7 -r e32b48848add src/http/modules/ngx_http_ssl_module.c
--- a/src/http/modules/ngx_http_ssl_module.c	Thu Oct 13 16:18:56 2022 +0400
+++ b/src/http/modules/ngx_http_ssl_module.c	Mon Oct 17 16:24:53 2022 +0400
@@ -1093,7 +1093,7 @@ ngx_http_ssl_session_cache(ngx_conf_t *c
                 len++;
             }
 
-            if (len == 0) {
+            if (len == 0 || j == value[i].len) {
                 goto invalid;
             }
 
@@ -1183,7 +1183,7 @@ ngx_http_ssl_ocsp_cache(ngx_conf_t *cf, 
         len++;
     }
 
-    if (len == 0) {
+    if (len == 0 || j == value[1].len) {
         goto invalid;
     }
 
diff -r 81b4326daac7 -r e32b48848add src/mail/ngx_mail_ssl_module.c
--- a/src/mail/ngx_mail_ssl_module.c	Thu Oct 13 16:18:56 2022 +0400
+++ b/src/mail/ngx_mail_ssl_module.c	Mon Oct 17 16:24:53 2022 +0400
@@ -682,7 +682,7 @@ ngx_mail_ssl_session_cache(ngx_conf_t *c
                 len++;
             }
 
-            if (len == 0) {
+            if (len == 0 || j == value[i].len) {
                 goto invalid;
             }
 
diff -r 81b4326daac7 -r e32b48848add src/stream/ngx_stream_ssl_module.c
--- a/src/stream/ngx_stream_ssl_module.c	Thu Oct 13 16:18:56 2022 +0400
+++ b/src/stream/ngx_stream_ssl_module.c	Mon Oct 17 16:24:53 2022 +0400
@@ -1073,7 +1073,7 @@ ngx_stream_ssl_session_cache(ngx_conf_t 
                 len++;
             }
 
-            if (len == 0) {
+            if (len == 0 || j == value[i].len) {
                 goto invalid;
             }