[PATCH] user.exe: Avoid truncating strcmp result (Coverity)

[Marcus Meissner]

Hi,

strcmp() might return a full 32bit wide difference in optimized
strcmp cases, so we need to avoid truncating the upper 16 bits.

(mysql security flaw resulting from such a truncation:

https://community.rapid7.com/community/metasploit/blog/2012/06/11/cve-2012-2122-a-tragically-comedic-security-flaw-in-mysql
)

Ciao, Marcus
---
 dlls/user.exe16/user.c |    9 ++++++++-
 1 files changed, 8 insertions(+), 1 deletions(-)

diff --git a/dlls/user.exe16/user.c b/dlls/user.exe16/user.c
index 705620b..c1064b3 100644
--- a/dlls/user.exe16/user.c
+++ b/dlls/user.exe16/user.c
@@ -2557,7 +2557,14 @@ INT16 WINAPIV wsprintf16( LPSTR buffer, LPCSTR spec, VA_LIST16 valist )
  */
 INT16 WINAPI lstrcmp16( LPCSTR str1, LPCSTR str2 )
 {
-    return strcmp( str1, str2 );
+    int ret;
+    /* Looks too complicated, but in optimized strcpy we might get
+    * a 32bit wide difference and would truncate it to 16 bit, so
+     * erronously returning equality. */
+    ret = strcmp( str1, str2 );
+    if (ret < 0) return -1;
+    if (ret > 0) return  1;
+    return 0;
 }
 
 
-- 
1.7.3.4