[PATCH] ntdll: Only set owned bits in RTL_BITMAP

[janisozaur at gmail.com]

From: Michał Janiszewski <janisozaur at gmail.com>

Signed-off-by: Michał Janiszewski <janisozaur at gmail.com>
---
 dlls/ntdll/rtlbitmap.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/dlls/ntdll/rtlbitmap.c b/dlls/ntdll/rtlbitmap.c
index 318f6fcbd4..c3e9385ec0 100644
--- a/dlls/ntdll/rtlbitmap.c
+++ b/dlls/ntdll/rtlbitmap.c
@@ -157,7 +157,8 @@ VOID WINAPI RtlSetBits(PRTL_BITMAP lpBits, ULONG ulStart, ULONG ulCount)
       USHORT initialWord = NTDLL_maskBits[ulCount] << (ulStart & 7);
 
       *lpOut++ |= (initialWord & 0xff);
-      *lpOut |= (initialWord >> 8);
+      if (lpOut < ((BYTE *)lpBits->Buffer) + (lpBits->SizeOfBitMap / 8))
+        *lpOut |= (initialWord >> 8);
       return;
     }
   }
@@ -218,7 +219,8 @@ VOID WINAPI RtlClearBits(PRTL_BITMAP lpBits, ULONG ulStart, ULONG ulCount)
       USHORT initialWord = ~(NTDLL_maskBits[ulCount] << (ulStart & 7));
 
       *lpOut++ &= (initialWord & 0xff);
-      *lpOut &= (initialWord >> 8);
+      if (lpOut < ((BYTE *)lpBits->Buffer) + (lpBits->SizeOfBitMap / 8))
+        *lpOut &= (initialWord >> 8);
       return;
     }
   }
-- 
2.17.1