[PATCH v7 5/7] ntdll: Rework RtlExpandEnvironmentStrings/_U to account for corner cases.

27 Jul 2024

From: Fabian Maurer dark.shadow4@web.de
---
 dlls/kernel32/tests/environ.c | 20 +++++-----
 dlls/ntdll/env.c              | 15 ++++++--
 dlls/ntdll/tests/env.c        | 70 +++++++++++++++++------------------
 3 files changed, 57 insertions(+), 48 deletions(-)

diff --git a/dlls/kernel32/tests/environ.c index 6a7844480cc..ec5842c4a9e 100644 --- a/dlls/kernel32/tests/environ.c +++ b/dlls/kernel32/tests/environ.c @@ -404,25 +404,25 @@ static void test_ExpandEnvir /*  6 */ { L"Long long value", /*  7 */ { L"%TVAR% long long", /*  8 */ { L"%TVAR% long long", -        /*  9 */ { L"%TVAR% long long", -        /* 10 */ { L"%TVAR% long long", +        /*  9 */ { L"%TVAR% long long", +        /* 10 */ { L"%TVAR% long long", /* 11 */ { L"%TVAR% long long", /* 12 */ { L"%TVAR% long long", /* 13 */ { L"%TVAR% long long", /* 14 */ { L"%TVAR% long long", /* 15 */ { L"%TVAR% long long", -        /* 16 */ { L"%TVAR%%TVAR% long", +        /* 16 */ { L"%TVAR%%TVAR% long", /* 17 */ { L"%TVAR%%TVAR% long", -        /* 18 */ { L"%TVAR%%TVAR% long", -        /* 19 */ { L"%TVAR%%TVAR% long", +        /* 18 */ { L"%TVAR%%TVAR% long", +        /* 19 */ { L"%TVAR%%TVAR% long", /* 20 */ { L"%TVAR%%TVAR% long", /* 21 */ { L"%TVAR%%TVAR% long", /* 22 */ { L"%TVAR%%TVAR% long", /* 23 */ { L"%TVAR%%TVAR% long", /* 24 */ { L"%TVAR% %TVAR% long", /* 25 */ { L"%TVAR% %TVAR% long", -        /* 26 */ { L"%TVAR% %TVAR% long", -        /* 27 */ { L"%TVAR% %TVAR% long", +        /* 26 */ { L"%TVAR% %TVAR% long", +        /* 27 */ { L"%TVAR% %TVAR% long", /* 28 */ { L"%TVAR% %TVAR% long", /* 29 */ { L"%TVAR% %TVAR% long", /* 30 */ { L"%TVAR% %TVAR% long", @@ -502,14 +502,14 @@ static void test_ExpandEnvir /*  6 */ { "Long long value", /*  7 */ { "%TVAR% long long", /*  8 */ { "%TVAR% long long", -        /*  9 */ { "%TVAR% long long", -        /* 10 */ { "%TVAR% long long", +        /*  9 */ { "%TVAR% long long", +        /* 10 */ { "%TVAR% long long", /* 11 */ { "%TVAR% long long", /* 12 */ { "%TVAR% long long", /* 13 */ { "%TVAR% long long", /* 14 */ { "%TVAR% long long", /* 15 */ { "%TVAR% long long", -        /* 16 */ { "%TVAR%%TVAR% long", +        /* 16 */ { "%TVAR%%TVAR% long", /* 17 */ { "%TVAR%%TVAR% long", /* 18 */ { "%TVAR%%TVAR% long", /* 19 */ { "%TVAR%%TVAR% long", diff --git a/dlls/ntdll/env.c b/dlls/ntdll/env.c index 720597dcaf9..58bfdbb9fe8 100644 --- a/dlls/ntdll/env.c +++ b/dlls/ntdll/env.c @@ -384,7 +384,7 @@ done: NTSTATUS WINAPI RtlExpandEnvironmentStrings(

{ -    SIZE_T len, total_size = 1;  /* 1 for +    SIZE_T len, copy, total_size = 1;  /* LPCWSTR env, var;

b/dlls/kernel32/tests/environ.c onmentStringsW(void) L"Long long value",        17, 16 }, L"abcdefghijklmnopqrstuv",  0, 15, TRUE }, L"",                        1, 15, TRUE }, L"",                        2, 15, TRUE, TRUE }, L"",                        4, 15, TRUE, TRUE }, L"",                        2, 15, TRUE }, L"",                        4, 15, TRUE }, L"WINE",                    5, 15, TRUE }, L"WINE fghijklmnopqrstuv",  6, 15, TRUE, TRUE }, L"WINE lghijklmnopqrstuv",  7, 15, TRUE, TRUE }, L"WINE long long",         15, 15 }, L"WINE long long",         16, 15 }, L"",                        4, 14, TRUE, TRUE }, L"",                        4, 14, TRUE }, L"WINE",                    5, 14, TRUE }, L"WINE",                    6, 14, TRUE, TRUE }, L"WINE",                    8, 14, TRUE, TRUE }, L"WINE",                    6, 14, TRUE }, L"WINE",                    8, 14, TRUE }, L"WINEWINE",                9, 14, TRUE }, L"WINEWINE jklmnopqrstuv", 10, 14, TRUE, TRUE }, L"WINEWINE long",          14, 14 }, L"WINEWINE long",          15, 14 }, L"WINE",                    5, 15, TRUE }, L"WINE ",                   6, 15, TRUE }, L"WINE ",                   8, 15, TRUE, TRUE }, L"WINE ",                   9, 15, TRUE, TRUE }, L"WINE ",                   8, 15, TRUE }, L"WINE ",                   9, 15, TRUE }, L"WINE WINE",              10, 15, TRUE }, L"WINE WINE klmnopqrstuv", 11, 15, TRUE, TRUE }, L"WINE WINE llmnopqrstuv", 12, 15, TRUE, TRUE }, onmentStringsA(void) "Long long value",   17, 16 }, "",                   0, 16, TRUE, TRUE, TRUE }, "",                   1, 16, TRUE, FALSE, TRUE }, "",                   2, 16, TRUE, TRUE, TRUE }, "",                   4, 16, TRUE, TRUE, TRUE }, "",                   2, 16, TRUE, FALSE, TRUE }, "",                   4, 16, TRUE, FALSE, TRUE }, "",                   5, 16, TRUE, TRUE, TRUE }, "",                   6, 16, TRUE, TRUE, TRUE }, "",                   7, 16, TRUE, TRUE, TRUE }, "",                  15, 16, FALSE, TRUE, TRUE }, "WINE long long",    16, 15 }, "",                   4, 15, TRUE, TRUE, TRUE }, "",                   4, 15, TRUE, FALSE, TRUE }, "",                   5, 15, TRUE, TRUE, TRUE }, "",                   6, 15, TRUE, TRUE, TRUE }, "",                   8, 15, TRUE, TRUE, TRUE }, const WCHAR *renv, WCHAR *src, SIZE_T src_len, WCHAR *dst, SIZE_T count, SIZE_T *plen ) terminating '\0' */ 1 for terminating '\0' */
if (!renv)
@@ -402,6 +402,7 @@ NTSTATUS WINAPI RtlExpandEnvironmentStrings( const WCHAR *renv, WCHAR *src, SIZE
             var = src;
             src += len;
             src_len -= len;
+            copy = len;
         }
         else  /* we are at the start of a variable */
         {
@@ -413,6 +414,11 @@ NTSTATUS WINAPI RtlExpandEnvironmentStrings( const WCHAR *renv, WCHAR *src, SIZE
                     src += len + 1;  /* Skip the variable name */
                     src_len -= len + 1;
                     len = wcslen(var);
+                    copy = len;
+                    if (count <= copy) /* Either copy the entire value, or nothing at all */
+                        copy = 0;
+                    if (dst && count)  /* When the variable is the last thing that fits into dst, the string is null terminated */
+                       dst[copy] = 0;  /* Either right after, or if it doesn't fit, where it would start */
                 }
                 else
                 {
@@ -420,6 +426,7 @@ NTSTATUS WINAPI RtlExpandEnvironmentStrings( const WCHAR *renv, WCHAR *src, SIZE
                     len++;
                     src += len;
                     src_len -= len;
+                    copy = len;
                 }
             }
             else  /* unfinished variable name, ignore it */
@@ -427,15 +434,17 @@ NTSTATUS WINAPI RtlExpandEnvironmentStrings( const WCHAR *renv, WCHAR *src, SIZE
                 var = src;
                 src += len;
                 src_len = 0;
+                copy = len;
             }
         }
         total_size += len;
         if (dst)
         {
             if (count < len) len = count;
-            memcpy(dst, var, len * sizeof(WCHAR));
+            if (count <= copy) copy = count ? count - 1 : 0; /* If the buffer is too small, we copy one character less */
+            memcpy(dst, var, copy * sizeof(WCHAR));
             count -= len;
-            dst += len;
+            dst += copy;
         }
     }
diff --git a/dlls/ntdll/tests/env.c b/dlls/ntdll/tests/env.c
index ad653afa439..1760501a434 100644
--- a/dlls/ntdll/tests/env.c
+++ b/dlls/ntdll/tests/env.c
@@ -260,52 +260,52 @@ static void test_RtlExpandEnvironmentStrings(void)
     } tests[] =
     {
         /*  0 */ { L"Long long value",       L"abcdefghijklmnopqrstuv",  0, 16 },
-        /*  1 */ { L"Long long value",       L"abcdefghijklmnopqrstuv",  1, 16, TRUE },
-        /*  2 */ { L"Long long value",       L"Lbcdefghijklmnopqrstuv",  2, 16, TRUE },
-        /*  3 */ { L"Long long value",       L"Locdefghijklmnopqrstuv",  3, 16, TRUE },
-        /*  4 */ { L"Long long value",       L"Long long valuopqrstuv", 15, 16, TRUE },
+        /*  1 */ { L"Long long value",       L"abcdefghijklmnopqrstuv",  1, 16 },
+        /*  2 */ { L"Long long value",       L"Lbcdefghijklmnopqrstuv",  2, 16 },
+        /*  3 */ { L"Long long value",       L"Locdefghijklmnopqrstuv",  3, 16 },
+        /*  4 */ { L"Long long value",       L"Long long valuopqrstuv", 15, 16 },
         /*  5 */ { L"Long long value",       L"Long long value",        16, 16 },
         /*  6 */ { L"Long long value",       L"Long long value",        17, 16 },
         /*  7 */ { L"%TVAR% long long",      L"abcdefghijklmnopqrstuv",  0, 15 },
-        /*  8 */ { L"%TVAR% long long",      L"",                        1, 15, TRUE },
-        /*  9 */ { L"%TVAR% long long",      L"",                        2, 15, TRUE },
-        /* 10 */ { L"%TVAR% long long",      L"",                        4, 15, TRUE },
-        /* 11 */ { L"%TVAR% long long",      L"WINE",                    5, 15, TRUE },
-        /* 12 */ { L"%TVAR% long long",      L"WINE fghijklmnopqrstuv",  6, 15, TRUE },
-        /* 13 */ { L"%TVAR% long long",      L"WINE lghijklmnopqrstuv",  7, 15, TRUE },
+        /*  8 */ { L"%TVAR% long long",      L"",                        1, 15 },
+        /*  9 */ { L"%TVAR% long long",      L"",                        2, 15 },
+        /* 10 */ { L"%TVAR% long long",      L"",                        4, 15 },
+        /* 11 */ { L"%TVAR% long long",      L"WINE",                    5, 15 },
+        /* 12 */ { L"%TVAR% long long",      L"WINE fghijklmnopqrstuv",  6, 15 },
+        /* 13 */ { L"%TVAR% long long",      L"WINE lghijklmnopqrstuv",  7, 15 },
         /* 14 */ { L"%TVAR% long long",      L"WINE long long",         15, 15 },
         /* 15 */ { L"%TVAR% long long",      L"WINE long long",         16, 15 },
-        /* 16 */ { L"%TVAR%%TVAR% long",     L"",                        4, 14, TRUE },
-        /* 17 */ { L"%TVAR%%TVAR% long",     L"WINE",                    5, 14, TRUE },
-        /* 18 */ { L"%TVAR%%TVAR% long",     L"WINE",                    6, 14, TRUE },
-        /* 19 */ { L"%TVAR%%TVAR% long",     L"WINE",                    8, 14, TRUE },
-        /* 20 */ { L"%TVAR%%TVAR% long",     L"WINEWINE",                9, 14, TRUE },
-        /* 21 */ { L"%TVAR%%TVAR% long",     L"WINEWINE jklmnopqrstuv", 10, 14, TRUE },
+        /* 16 */ { L"%TVAR%%TVAR% long",     L"",                        4, 14 },
+        /* 17 */ { L"%TVAR%%TVAR% long",     L"WINE",                    5, 14 },
+        /* 18 */ { L"%TVAR%%TVAR% long",     L"WINE",                    6, 14 },
+        /* 19 */ { L"%TVAR%%TVAR% long",     L"WINE",                    8, 14 },
+        /* 20 */ { L"%TVAR%%TVAR% long",     L"WINEWINE",                9, 14 },
+        /* 21 */ { L"%TVAR%%TVAR% long",     L"WINEWINE jklmnopqrstuv", 10, 14 },
         /* 22 */ { L"%TVAR%%TVAR% long",     L"WINEWINE long",          14, 14 },
         /* 23 */ { L"%TVAR%%TVAR% long",     L"WINEWINE long",          15, 14 },
-        /* 24 */ { L"%TVAR% %TVAR% long",    L"WINE",                    5, 15, TRUE },
-        /* 25 */ { L"%TVAR% %TVAR% long",    L"WINE ",                   6, 15, TRUE },
-        /* 26 */ { L"%TVAR% %TVAR% long",    L"WINE ",                   8, 15, TRUE },
-        /* 27 */ { L"%TVAR% %TVAR% long",    L"WINE ",                   9, 15, TRUE },
-        /* 28 */ { L"%TVAR% %TVAR% long",    L"WINE WINE",              10, 15, TRUE },
-        /* 29 */ { L"%TVAR% %TVAR% long",    L"WINE WINE klmnopqrstuv", 11, 15, TRUE },
-        /* 30 */ { L"%TVAR% %TVAR% long",    L"WINE WINE llmnopqrstuv", 12, 15, TRUE },
-        /* 31 */ { L"%TVAR% %TVAR% long",    L"WINE WINE lonnopqrstuv", 14, 15, TRUE },
+        /* 24 */ { L"%TVAR% %TVAR% long",    L"WINE",                    5, 15 },
+        /* 25 */ { L"%TVAR% %TVAR% long",    L"WINE ",                   6, 15 },
+        /* 26 */ { L"%TVAR% %TVAR% long",    L"WINE ",                   8, 15 },
+        /* 27 */ { L"%TVAR% %TVAR% long",    L"WINE ",                   9, 15 },
+        /* 28 */ { L"%TVAR% %TVAR% long",    L"WINE WINE",              10, 15 },
+        /* 29 */ { L"%TVAR% %TVAR% long",    L"WINE WINE klmnopqrstuv", 11, 15 },
+        /* 30 */ { L"%TVAR% %TVAR% long",    L"WINE WINE llmnopqrstuv", 12, 15 },
+        /* 31 */ { L"%TVAR% %TVAR% long",    L"WINE WINE lonnopqrstuv", 14, 15 },
         /* 32 */ { L"%TVAR% %TVAR% long",    L"WINE WINE long",         15, 15 },
         /* 33 */ { L"%TVAR% %TVAR% long",    L"WINE WINE long",         16, 15 },
-        /* 34 */ { L"%TVAR2% long long",     L"abcdefghijklmnopqrstuv",  1, 18, TRUE },
-        /* 35 */ { L"%TVAR2% long long",     L"%bcdefghijklmnopqrstuv",  2, 18, TRUE },
-        /* 36 */ { L"%TVAR2% long long",     L"%TVdefghijklmnopqrstuv",  4, 18, TRUE },
-        /* 37 */ { L"%TVAR2% long long",     L"%TVAR2ghijklmnopqrstuv",  7, 18, TRUE },
-        /* 38 */ { L"%TVAR2% long long",     L"%TVAR2%hijklmnopqrstuv",  8, 18, TRUE },
-        /* 39 */ { L"%TVAR2% long long",     L"%TVAR2% ijklmnopqrstuv",  9, 18, TRUE },
-        /* 40 */ { L"%TVAR2% long long",     L"%TVAR2% ljklmnopqrstuv", 10, 18, TRUE },
+        /* 34 */ { L"%TVAR2% long long",     L"abcdefghijklmnopqrstuv",  1, 18 },
+        /* 35 */ { L"%TVAR2% long long",     L"%bcdefghijklmnopqrstuv",  2, 18 },
+        /* 36 */ { L"%TVAR2% long long",     L"%TVdefghijklmnopqrstuv",  4, 18 },
+        /* 37 */ { L"%TVAR2% long long",     L"%TVAR2ghijklmnopqrstuv",  7, 18 },
+        /* 38 */ { L"%TVAR2% long long",     L"%TVAR2%hijklmnopqrstuv",  8, 18 },
+        /* 39 */ { L"%TVAR2% long long",     L"%TVAR2% ijklmnopqrstuv",  9, 18 },
+        /* 40 */ { L"%TVAR2% long long",     L"%TVAR2% ljklmnopqrstuv", 10, 18 },
         /* 41 */ { L"%TVAR2% long long",     L"%TVAR2% long long",      18, 18 },
         /* 42 */ { L"%TVAR2% long long",     L"%TVAR2% long long",      19, 18 },
-        /* 43 */ { L"%TVAR long long",       L"abcdefghijklmnopqrstuv",  1, 16, TRUE },
-        /* 44 */ { L"%TVAR long long",       L"%bcdefghijklmnopqrstuv",  2, 16, TRUE },
-        /* 45 */ { L"%TVAR long long",       L"%Tcdefghijklmnopqrstuv",  3, 16, TRUE },
-        /* 46 */ { L"%TVAR long long",       L"%TVAR long lonopqrstuv", 15, 16, TRUE },
+        /* 43 */ { L"%TVAR long long",       L"abcdefghijklmnopqrstuv",  1, 16 },
+        /* 44 */ { L"%TVAR long long",       L"%bcdefghijklmnopqrstuv",  2, 16 },
+        /* 45 */ { L"%TVAR long long",       L"%Tcdefghijklmnopqrstuv",  3, 16 },
+        /* 46 */ { L"%TVAR long long",       L"%TVAR long lonopqrstuv", 15, 16 },
         /* 47 */ { L"%TVAR long long",       L"%TVAR long long",        16, 16 },
         /* 48 */ { L"%TVAR long long",       L"%TVAR long long",        17, 16 },
     };
-- 
GitLab


https://gitlab.winehq.org/wine/wine/-/merge_requests/4045

    

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[PATCH v7 5/7] ntdll: Rework RtlExpandEnvironmentStrings/_U to account for corner cases.