From: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Date: Thu, 5 Apr 2018 01:50:53 +0000 (+0200)
Subject: tools/xenpmd: fix possible '\0' truncation
X-Git-Tag: 4.11.0-rc1~53
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=938c8f53b1f80175c6f7a1399efdb984abb0cb8b;p=xen.git

tools/xenpmd: fix possible '\0' truncation

gcc-8 complains:
    xenpmd.c:207:9: error: 'strncpy' specified bound 32 equals destination size [-Werror=stringop-truncation]
             strncpy(info->oem_info, attrib_value, 32);
             ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    xenpmd.c:201:9: error: 'strncpy' specified bound 32 equals destination size [-Werror=stringop-truncation]
             strncpy(info->battery_type, attrib_value, 32);
             ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    xenpmd.c:195:9: error: 'strncpy' specified bound 32 equals destination size [-Werror=stringop-truncation]
             strncpy(info->serial_number, attrib_value, 32);
             ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    xenpmd.c:189:9: error: 'strncpy' specified bound 32 equals destination size [-Werror=stringop-truncation]
             strncpy(info->model_number, attrib_value, 32);
             ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Copy 31 chars, then make sure terminating '\0' is present. Those fields
are passed to strlen and as '%s' for snprintf later.

Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Release-Acked-by: Juergen Gross <jgross@suse.com>
---

diff --git a/tools/xenpmd/xenpmd.c b/tools/xenpmd/xenpmd.c
index 689c8fd670..56412a9a81 100644
--- a/tools/xenpmd/xenpmd.c
+++ b/tools/xenpmd/xenpmd.c
@@ -186,25 +186,29 @@ void set_attribute_battery_info(char *attrib_name,
 
     if ( strstr(attrib_name, "model number") ) 
     {
-        strncpy(info->model_number, attrib_value, 32);
+        strncpy(info->model_number, attrib_value, 31);
+        info->model_number[31] = '\0';
         return;
     }
 
     if ( strstr(attrib_name, "serial number") ) 
     {
-        strncpy(info->serial_number, attrib_value, 32);
+        strncpy(info->serial_number, attrib_value, 31);
+        info->serial_number[31] = '\0';
         return;
     }
 
     if ( strstr(attrib_name, "battery type") ) 
     {
-        strncpy(info->battery_type, attrib_value, 32);
+        strncpy(info->battery_type, attrib_value, 31);
+        info->battery_type[31] = '\0';
         return;
     }
 
     if ( strstr(attrib_name, "OEM info") ) 
     {
-        strncpy(info->oem_info, attrib_value, 32);
+        strncpy(info->oem_info, attrib_value, 31);
+        info->oem_info[31] = '\0';
         return;
     }