Actually Fixed: Out of Bounds Potential Read on Pattern Not Found in …

…Vectorised Impl
Reloaded-Project · Aug 23, 2023 · 2871fe6 · 2871fe6
1 parent 8a41729
commit 2871fe6
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Showing 2 changed files with 2 additions and 2 deletions.
diff --git a/Reloaded.Memory.Sigscan/Scanner_AVX2.cs b/Reloaded.Memory.Sigscan/Scanner_AVX2.cs
@@ -55,7 +55,7 @@ public static PatternScanResult FindPatternAvx2(byte* data, int dataLength, stri
         int matchTableLength = matchTable.Length;
 
         var firstByteVec     = Vector256.Create(patternData.Bytes[patternData.LeadingIgnoreCount]);
-        int searchLength = dataLength - Math.Max(patternData.Bytes.Length >> 5 << 5, AvxRegisterLength); // bitshift rounds down
+        int searchLength = dataLength - Math.Max((patternData.Bytes.Length + 31) >> 5 << 5, AvxRegisterLength); // shift by 5 == 32
 
         int leadingIgnoreCount = patternData.LeadingIgnoreCount;
         ref var pVec = ref patternVectors[0];

diff --git a/Reloaded.Memory.Sigscan/Scanner_SSE2.cs b/Reloaded.Memory.Sigscan/Scanner_SSE2.cs
@@ -54,7 +54,7 @@ public static PatternScanResult FindPatternSse2(byte* data, int dataLength, stri
         int matchTableLength = matchTable.Length;
 
         var firstByteVec  = Vector128.Create(patternData.Bytes[patternData.LeadingIgnoreCount]);
-        int searchLength = dataLength - Math.Max(patternData.Bytes.Length >> 4 << 4, SseRegisterLength); // bitshift rounds down
+        int searchLength = dataLength - Math.Max((patternData.Bytes.Length + 15) >> 4 << 4, SseRegisterLength); // shift by 4 == 16
 
         int leadingIgnoreCount = patternData.LeadingIgnoreCount;
         ref var pVec = ref patternVectors[0];