Re: [PATCH] x86/boot: Reject truncated acpi_rsdp= values

From: Borislav Petkov

Date: Thu Jun 18 2026 - 15:34:37 EST


On Thu, Jun 18, 2026 at 08:57:56PM +0200, Thorsten Blum wrote:
> Only far enough to avoid using a value the user didn't actually enter.

But the user did enter it.

And nothing in there tells her/him that they entered a wrong value. Only that
the value she entered magically turned into a 0.

So how is that helping said user fix the input?

And is there a real use case you're fixing here or is this something
hypothetical that *might* happen?

> A user can still shoot themselves in the foot by using a syntactically
> valid but wrong address. The check only rejects an overlong acpi_rsdp=
> value after cmdline_find_option() reports that it didn't fit in the
> buffer.

My question still stands paraphrazed: what *actual*, real use case are you
fixing here?

And how does your fix make anything better?

--
Regards/Gruss,
Boris.

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