Re: [PATCH] powerpc/64s: Fix copy-paste data exposure into newly created tasks

On Tue, 22 Jun 2021 15:30:36 +1000, Nicholas Piggin wrote:

copy-paste contains implicit "copy buffer" state that can contain
arbitrary user data (if the user process executes a copy instruction).
This could be snooped by another process if a context switch hits while
the state is live. So cp_abort is executed on context switch to clear
out possible sensitive data and prevent the leak.

cp_abort is done after the low level _switch(), which means it is never
reached by newly created tasks, so they could snoop on this buffer
between their first and second context switch.

[...]

Applied to powerpc/next.

[1/1] powerpc/64s: Fix copy-paste data exposure into newly created tasks
      https://git.kernel.org/powerpc/c/f35d2f249ef05b9671e7898f09ad89aa78f99122

cheers