From 8cfb648761229727fd66866092f7fa84dd3922fc Mon Sep 17 00:00:00 2001
From: Xinchen Hui <laruence@gmail.com>
Date: Tue, 10 Apr 2018 16:32:08 +0800
Subject: [PATCH] Fixed bug #76143 (Memory corruption: arbitrary NUL overwrite)

---
 NEWS                    |  3 +++
 sapi/phpdbg/phpdbg_io.c | 21 ++++++++-------------
 2 files changed, 11 insertions(+), 13 deletions(-)

diff --git a/NEWS b/NEWS
index 22b6d86c3ecce..dce15ca4dd7ed 100644
--- a/NEWS
+++ b/NEWS
@@ -22,6 +22,9 @@ PHP                                                                        NEWS
   . Fixed bug #76113 (mbstring does not build with Oniguruma 6.8.1).
     (chrullrich, cmb)
 
+- phpdbg:
+  . Fixed bug #76143 (Memory corruption: arbitrary NUL overwrite). (Laruence)
+
 - SPL:
   . Fixed bug #76131 (mismatch arginfo for splarray constructor). 
     (carusogabriel)
diff --git a/sapi/phpdbg/phpdbg_io.c b/sapi/phpdbg/phpdbg_io.c
index ee5a656b60669..1bf7227b1fd70 100644
--- a/sapi/phpdbg/phpdbg_io.c
+++ b/sapi/phpdbg/phpdbg_io.c
@@ -290,7 +290,7 @@ PHPDBG_API int phpdbg_create_listenable_socket(const char *addr, unsigned short
 			}
 		}
 
-		snprintf(port_buf, 7, "%u", port);
+		snprintf(port_buf, sizeof(port_buf), "%u", port);
 		if (!any_addr) {
 			rc = getaddrinfo(addr, port_buf, &hints, &res);
 		} else {
@@ -301,20 +301,18 @@ PHPDBG_API int phpdbg_create_listenable_socket(const char *addr, unsigned short
 #ifndef PHP_WIN32
 			if (rc == EAI_SYSTEM) {
 				char buf[128];
-				int wrote;
 
-				wrote = snprintf(buf, 128, "Could not translate address '%s'", addr);
-				buf[wrote] = '\0';
+				snprintf(buf, sizeof(buf), "Could not translate address '%s'", addr);
+
 				zend_quiet_write(PHPDBG_G(io)[PHPDBG_STDERR].fd, buf, strlen(buf));
 
 				return sock;
 			} else {
 #endif
 				char buf[256];
-				int wrote;
 
-				wrote = snprintf(buf, 256, "Host '%s' not found. %s", addr, estrdup(gai_strerror(rc)));
-				buf[wrote] = '\0';
+				snprintf(buf, sizeof(buf), "Host '%s' not found. %s", addr, estrdup(gai_strerror(rc)));
+
 				zend_quiet_write(PHPDBG_G(io)[PHPDBG_STDERR].fd, buf, strlen(buf));
 
 				return sock;
@@ -324,13 +322,10 @@ PHPDBG_API int phpdbg_create_listenable_socket(const char *addr, unsigned short
 			return sock;
 		}
 
-		if((sock = socket(res->ai_family, res->ai_socktype, res->ai_protocol)) == -1) {
-			char buf[128];
-			int wrote;
+		if ((sock = socket(res->ai_family, res->ai_socktype, res->ai_protocol)) == -1) {
+			const char *msg = "Unable to create socket";
 
-			wrote = sprintf(buf, "Unable to create socket");
-			buf[wrote] = '\0';
-			zend_quiet_write(PHPDBG_G(io)[PHPDBG_STDERR].fd, buf, strlen(buf));
+			zend_quiet_write(PHPDBG_G(io)[PHPDBG_STDERR].fd, msg, strlen(msg));
 
 			return sock;
 		}