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⚔ Commemorated today: The Downfall of Knight Capital (2012)Saint GhostWrite, Who Wrote Where He Shouldn't
Patron of RISC-V processors, vector extensions, and ghosts who sign on your behalf.
Life
In the summer of 2024 researchers at CISPA found that some vector instructions in T-Head's XuanTie C910 and C920 cores wrote straight to physical memory, skipping virtual memory and with it every form of isolation. Any unprivileged program could write anywhere: into the kernel, into other processes, even into peripherals. Being a flaw in the silicon, no patch could erase it.
Prayer
O Saint GhostWrite, who writes with an invisible hand on other people's memory, let our instructions always go through the MMU. Amen.
How to celebrate
Celebrated by disabling the vector extension, giving up half the CPU to save the other half.
Write without a virtual address and you write everyone's fate.