File ImageMagick-CVE-2020-27758.patch of Package ImageMagick.30356
Index: ImageMagick-7.0.7-34/coders/txt.c
===================================================================
--- ImageMagick-7.0.7-34.orig/coders/txt.c 2018-05-20 17:55:43.000000000 +0200
+++ ImageMagick-7.0.7-34/coders/txt.c 2020-12-08 17:29:23.419461082 +0100
@@ -561,16 +561,16 @@ static Image *ReadTXTImage(const ImageIn
green+=(range+1)/2.0;
blue+=(range+1)/2.0;
}
- pixel.red=(MagickRealType) ScaleAnyToQuantum((QuantumAny) (red+0.5),
- range);
- pixel.green=(MagickRealType) ScaleAnyToQuantum((QuantumAny) (green+0.5),
- range);
- pixel.blue=(MagickRealType) ScaleAnyToQuantum((QuantumAny) (blue+0.5),
- range);
- pixel.black=(MagickRealType) ScaleAnyToQuantum((QuantumAny) (black+0.5),
- range);
- pixel.alpha=(MagickRealType) ScaleAnyToQuantum((QuantumAny) (alpha+0.5),
- range);
+ pixel.red=(MagickRealType) ScaleAnyToQuantum((QuantumAny)
+ MagickMax(red+0.5,0.0),range);
+ pixel.green=(MagickRealType) ScaleAnyToQuantum((QuantumAny)
+ MagickMax(green+0.5,0.0),range);
+ pixel.blue=(MagickRealType) ScaleAnyToQuantum((QuantumAny)
+ MagickMax(blue+0.5,0.0),range);
+ pixel.black=(MagickRealType) ScaleAnyToQuantum((QuantumAny)
+ MagickMax(black+0.5,0.0),range);
+ pixel.alpha=(MagickRealType) ScaleAnyToQuantum((QuantumAny)
+ MagickMax(alpha+0.5,0.0),range);
q=GetAuthenticPixels(image,(ssize_t) x_offset,(ssize_t) y_offset,1,1,
exception);
if (q == (Quantum *) NULL)