Re: [PATCH] ARM: fault: Implement copy_from_kernel_nofault_allowed()

Mark Brown
2024-01-23T19:02:28Z

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On Mon, Jan 22, 2024 at 05:12:38PM -0800, Kees Cook wrote:
> Under PAN emulation when dumping backtraces from things like the
> LKDTM EXEC_USERSPACE test[1], a double fault (which would hang a CPU)
> would happen because of dump_instr() attempting to read a userspace
> address. Make sure copy_from_kernel_nofault() does not attempt this
> any more.

This appears to fix the original issue:

https://lava.sirena.org.uk/scheduler/job/497571

(though so did your earlier patch) so:

Tested-by: Mark Brown <broonie@kernel.org>

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