Hi, The stack protector functionality on x86_64 uses %gs:0x28 (%gs is the percpu area) for __stack_chk_guard, and all other architectures use a global variable instead. This means we never change the stack canary on non-x86 architectures which allows for a leak in one task to expose the canary in another task.
I'm curious what thoughts people may have about how to get this correctly implemented. Teaching the compiler about per-cpu data sounds exciting. :) -Kees -- Kees Cook Pixel Security
