[PATCH v2 0/1] MR9309: reg: Make sure empty is big enough.

[Yuxuan Shui (＠yshui)]

We access data[1], so empty needs to have a size of 2.

Found by ASan.

--
  v2: reg: Fix out-of-bound read when string is empty.

https://gitlab.winehq.org/wine/wine/-/merge_requests/9309

[PATCH v2 1/1] reg: Fix out-of-bound read when string is empty.

[Yuxuan Shui]

From: Yuxuan Shui

Found by ASan.
---
 programs/reg/add.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/programs/reg/add.c b/programs/reg/add.c
index e0cd0373339..484ace32d30 100644
--- a/programs/reg/add.c
+++ b/programs/reg/add.c
@@ -52,10 +52,12 @@ static BOOL get_regdata(const WCHAR *data, DWORD reg_type, WCHAR separator,
                         BYTE **data_bytes, DWORD *size_bytes)
 {
     static const WCHAR empty;
+    int base;

*size_bytes = 0;

if (!data) data = ∅
+    base = data[0] && towlower(data[1]) == 'x' ? 16 : 10;

switch (reg_type)
     {
@@ -74,7 +76,7 @@ static BOOL get_regdata(const WCHAR *data, DWORD reg_type, WCHAR separator,
         {
             LPWSTR rest;
             unsigned long val;
-            val = wcstoul(data, &rest, (towlower(data[1]) == 'x') ? 16 : 10);
+            val = wcstoul(data, &rest, base);
             if (*rest || data[0] == '-' || (val == ~0u && errno == ERANGE)) {
                 output_message(STRING_MISSING_NUMBER);
                 return FALSE;
@@ -89,7 +91,7 @@ static BOOL get_regdata(const WCHAR *data, DWORD reg_type, WCHAR separator,
             WCHAR *rest;
             UINT64 val;

-            val = _wcstoui64(data, &rest, (towlower(data[1]) == 'x') ? 16 : 10);
+            val = _wcstoui64(data, &rest, base);
             if (*rest || (val == ~0ull && errno == ERANGE))
             {
                 output_message(STRING_MISSING_NUMBER);