[GIT PULL] ACPI fix for v6.16-rc3

[GIT PULL] ACPI fix for v6.16-rc3

[Rafael J. Wysocki]

Hi Linus,

Please pull from the tag

 git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git \
 acpi-6.16-rc3

with top-most commit 6fcab2791543924d438e7fa49276d0998b0a069f

 ACPICA: Refuse to evaluate a method if arguments are missing

on top of commit e04c78d86a9699d136910cfc0bdcf01087e3267e

 Linux 6.16-rc2

to receive an ACPI fix for 6.16-rc3.

This fixes a crash in ACPICA while attempting to evaluate a control
method that expects more arguments than are being passed to it, which
was exposed by a defective firmware update from a prominent OEM on
multiple systems.

Thanks!


---------------

Rafael J. Wysocki (1):
      ACPICA: Refuse to evaluate a method if arguments are missing

---------------

 drivers/acpi/acpica/dsmethod.c | 7 +++++++
 1 file changed, 7 insertions(+)

Re: [GIT PULL] ACPI fix for v6.16-rc3

[Linus Torvalds]

On Sat, 21 Jun 2025 at 04:31, Rafael J. Wysocki <rafael@kernel.org> wrote:
>
> This fixes a crash in ACPICA while attempting to evaluate a control
> method that expects more arguments than are being passed to it, which
> was exposed by a defective firmware update from a prominent OEM on
> multiple systems.

Christ. Reading the ACPI issues page makes me go "D'oh".

Does anybody know what the heck Windows does in this situation? Does
it just happen to work because it uses random arguments and happily
dereferences bogus things without realizing, or does it do the "zero
out missing arguments" thing?

Because clearly that firmware bug must have passed entirely unnoticed
by people testing that thing on Windows...

              Linus

Re: [GIT PULL] ACPI fix for v6.16-rc3

[Rafael J. Wysocki]

On Sat, Jun 21, 2025 at 5:35 PM Linus Torvalds
<torvalds@linux-foundation.org> wrote:
>
> On Sat, 21 Jun 2025 at 04:31, Rafael J. Wysocki <rafael@kernel.org> wrote:
> >
> > This fixes a crash in ACPICA while attempting to evaluate a control
> > method that expects more arguments than are being passed to it, which
> > was exposed by a defective firmware update from a prominent OEM on
> > multiple systems.
>
> Christ. Reading the ACPI issues page makes me go "D'oh".
>
> Does anybody know what the heck Windows does in this situation? Does
> it just happen to work because it uses random arguments and happily
> dereferences bogus things without realizing, or does it do the "zero
> out missing arguments" thing?

Saket said: "I didn't run into this same bug on Windows though and the
interpreter just aborted out with a different error message saying
that this method already exists elsewhere. Maybe Windows thinks that
when RUCC is called with 2 args instead of 3, it is perhaps referring
to a different method with the same name, but warns that this name
already exists (AE_ALREADY_EXISTS)."

> Because clearly that firmware bug must have passed entirely unnoticed
> by people testing that thing on Windows...

Well, given the above, I'm wondering how it has been tested on
Windows.  It looks like somebody set a really low bar for the
verification of it.

Cheers, Rafael

Re: [GIT PULL] ACPI fix for v6.16-rc3

[pr-tracker-bot]

The pull request you sent on Sat, 21 Jun 2025 13:31:37 +0200:

> git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git acpi-6.16-rc3

has been merged into torvalds/linux.git:
https://git.kernel.org/torvalds/c/26fef998eb4df8781c038ffa4be8287219a8df0a

Thank you!

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