From 0692768e69d35545bbe47cc0a47cda70ef61dcc7 Mon Sep 17 00:00:00 2001
From: Ben Walker <benjamin.walker@intel.com>
Date: Wed, 18 Apr 2018 15:50:50 -0700
Subject: [PATCH] vhost: Fix negative array index use in
 spdk_vhost_set_socket_path

If basename was the string "", with length 0, it would have
resulted in accessing index -1 in dev_dirname.

Change-Id: Ib389f8fe220f5335a54f6a155a20fcca35b94e3e
Signed-off-by: Ben Walker <benjamin.walker@intel.com>
Reviewed-on: https://review.gerrithub.io/408253
Reviewed-by: Daniel Verkamp <daniel.verkamp@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Tested-by: SPDK Automated Test System <sys_sgsw@intel.com>
---
 lib/vhost/vhost.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/lib/vhost/vhost.c b/lib/vhost/vhost.c
index e639e7d5d..08f3ad813 100644
--- a/lib/vhost/vhost.c
+++ b/lib/vhost/vhost.c
@@ -1128,6 +1128,9 @@ spdk_vhost_set_socket_path(const char *basename)
 
 	if (basename && strlen(basename) > 0) {
 		ret = snprintf(dev_dirname, sizeof(dev_dirname) - 2, "%s", basename);
+		if (ret <= 0) {
+			return -EINVAL;
+		}
 		if ((size_t)ret >= sizeof(dev_dirname) - 2) {
 			SPDK_ERRLOG("Char dev dir path length %d is too long\n", ret);
 			return -EINVAL;