From 80a2771762f0411300ff01ec24d6481e8518dfff Mon Sep 17 00:00:00 2001
From: Maxim Dounin <mdounin@mdounin.ru>
Date: Wed, 4 Oct 2017 21:19:42 +0300
Subject: [PATCH] Fixed handling of unix sockets in $binary_remote_addr.

Previously, unix sockets were treated as AF_INET ones, and this may
result in buffer overread on Linux, where unbound unix sockets have
2-byte addresses.

Note that it is not correct to use just sun_path as a binary representation
for unix sockets.  This will result in an empty string for unbound unix
sockets, and thus behaviour of limit_req and limit_conn will change when
switching from $remote_addr to $binary_remote_addr.  As such, normal text
representation is used.

Reported by Stephan Dollberg.
---
 src/http/ngx_http_variables.c     | 12 ++++++++++++
 src/stream/ngx_stream_variables.c | 12 ++++++++++++
 2 files changed, 24 insertions(+)

diff --git a/src/http/ngx_http_variables.c b/src/http/ngx_http_variables.c
index 6138819dd..fea5186c4 100644
--- a/src/http/ngx_http_variables.c
+++ b/src/http/ngx_http_variables.c
@@ -1225,6 +1225,18 @@ ngx_http_variable_binary_remote_addr(ngx_http_request_t *r,
         break;
 #endif
 
+#if (NGX_HAVE_UNIX_DOMAIN)
+    case AF_UNIX:
+
+        v->len = r->connection->addr_text.len;
+        v->valid = 1;
+        v->no_cacheable = 0;
+        v->not_found = 0;
+        v->data = r->connection->addr_text.data;
+
+        break;
+#endif
+
     default: /* AF_INET */
         sin = (struct sockaddr_in *) r->connection->sockaddr;
 
diff --git a/src/stream/ngx_stream_variables.c b/src/stream/ngx_stream_variables.c
index 5d15f3a6d..092cc397e 100644
--- a/src/stream/ngx_stream_variables.c
+++ b/src/stream/ngx_stream_variables.c
@@ -481,6 +481,18 @@ ngx_stream_variable_binary_remote_addr(ngx_stream_session_t *s,
         break;
 #endif
 
+#if (NGX_HAVE_UNIX_DOMAIN)
+    case AF_UNIX:
+
+        v->len = s->connection->addr_text.len;
+        v->valid = 1;
+        v->no_cacheable = 0;
+        v->not_found = 0;
+        v->data = s->connection->addr_text.data;
+
+        break;
+#endif
+
     default: /* AF_INET */
         sin = (struct sockaddr_in *) s->connection->sockaddr;