Bound two values that texture packs and shader inis supply

A hashrange of 'addr,w,h = 0,0' passed validation (0 isn't bigger than the source),
became desc_.newW/newH, and ReplacedTexture::Prepare divides by them. A post-shader
SSAA level multiplies the render resolution with no upper bound, while the
texture-shader Scale sitting a few lines away is checked against 2..8.

GPU/Common/PostShader.cpp

@@ -163,6 +163,12 @@ void LoadPostShaderInfo(Draw::DrawContext *draw, const std::vector<Path> &direct
 					section.Get("OutputResolution", &info.outputResolution);
 					section.Get("Upscaling", &info.isUpscalingFilter);
 					section.Get("SSAA", &info.SSAAFilterLevel);
+					if (info.SSAAFilterLevel < 0 || info.SSAAFilterLevel > 8) {
+						// It multiplies the render resolution, and shader inis come from downloads -
+						// the neighbouring texture-shader "Scale" is bounded for the same reason.
+						WARN_LOG(Log::G3D, "Ignoring out-of-range SSAA level %d in shader '%s'", info.SSAAFilterLevel, info.section.c_str());
+						info.SSAAFilterLevel = 0;
+					}
 					section.Get("60fps", &info.requires60fps);
 					section.Get("UsePreviousFrame", &info.usePreviousFrame);
 

GPU/Common/TextureReplacer.cpp

@@ -490,6 +490,12 @@ void TextureReplacer::ParseHashRange(const std::string &key, const std::string &
 		return;
 	}
 
+	if (toW == 0 || toH == 0) {
+		// These end up as desc_.newW/newH, which ReplacedTexture::Prepare divides by.
+		ERROR_LOG(Log::TexReplacement, "Ignoring invalid hashrange %s = %s, range is empty", key.c_str(), value.c_str());
+		return;
+	}
+
 	const u64 rangeKey = ((u64)addr << 32) | ((u64)fromW << 16) | fromH;
 	hashranges_[rangeKey] = WidthHeightPair(toW, toH);
 }