[ros-diffs] [reactos] 11/21: [KERNEL32] Improve path name handling

[Timo Kreuzer]

https://git.reactos.org/?p=reactos.git;a=commitdiff;h=1b70ddd834ad81f7def62c...

commit 1b70ddd834ad81f7def62c3166dd560de3d23361
Author:     Timo Kreuzer [e-mail]
AuthorDate: Sat Apr 27 18:58:08 2019 +0200
Commit:     Timo Kreuzer [e-mail]
CommitDate: Sat Jul 20 13:56:18 2019 +0200

[KERNEL32] Improve path name handling

Fixes GCC 8 warning:
    dll/win32/kernel32/client/loader.c: In function 'LoadLibraryA':
    dll/win32/kernel32/client/loader.c:129:17: error: 'strncat' specified bound 13 equals source length [-Werror=stringop-overflow=]
                     strncat(PathBuffer, "\twain_32.dll", 13);
                     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
---
 dll/win32/kernel32/client/loader.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/dll/win32/kernel32/client/loader.c b/dll/win32/kernel32/client/loader.c
index 905f6ae7037..ec4111470a3 100644
--- a/dll/win32/kernel32/client/loader.c
+++ b/dll/win32/kernel32/client/loader.c
@@ -110,23 +110,25 @@ WINAPI
 DECLSPEC_HOTPATCH
 LoadLibraryA(LPCSTR lpLibFileName)
 {
+    static const CHAR TwainDllName[] = "twain_32.dll";
     LPSTR PathBuffer;
     UINT Len;
     HINSTANCE Result;

/* Treat twain_32.dll in a special way (what a surprise...) */
-    if (lpLibFileName && !_strcmpi(lpLibFileName, "twain_32.dll"))
+    if (lpLibFileName && !_strcmpi(lpLibFileName, TwainDllName))
     {
         /* Allocate space for the buffer */
-        PathBuffer = RtlAllocateHeap(RtlGetProcessHeap(), 0, MAX_PATH);
+        PathBuffer = RtlAllocateHeap(RtlGetProcessHeap(), 0, MAX_PATH + sizeof(ANSI_NULL));
         if (PathBuffer)
         {
             /* Get windows dir in this buffer */
-            Len = GetWindowsDirectoryA(PathBuffer, MAX_PATH - 13); /* 13 is sizeof of '\twain_32.dll' */
-            if (Len && Len < (MAX_PATH - 13))
+            Len = GetWindowsDirectoryA(PathBuffer, MAX_PATH);
+            if ((Len != 0) && (Len < (MAX_PATH - sizeof(TwainDllName) - sizeof('\'))))
             {
                 /* We successfully got windows directory. Concatenate twain_32.dll to it */
-                strncat(PathBuffer, "\twain_32.dll", 13);
+                PathBuffer[Len] = '\';
+                strcpy(&PathBuffer[Len + 1], TwainDllName);

/* And recursively call ourselves with a new string */
                 Result = LoadLibraryA(PathBuffer);